New South Wales Court of Appeal CITATION: AMABA PTY LTD (UNDER NSW ADMINISTERED WINDING UP) v BOOTH; AMACA PTY LTD (UNDER NSW ADMINISTERED WINDING UP) v BOOTH [2010] NSWCA 344 HEARING DATE(S): 2 and 3 September 2010 JUDGMENT DATE: 10 December 2010 JUDGMENT OF: Beazley JA at 1; Giles JA at 2; Basten JA at 3 In matter No 2010/138836: 1. Appeal dismissed with costs. DECISION: 2. Summons dismissed with costs. In matter No 2010/138880: 1. Appeal dismissed with costs. 2. Summons dismissed with costs. CATCHWORDS: APPEAL – civil – ground of appeal – error of law – no evidence and illogicality of reasoning - EVIDENCE – admissibility – expert evidence – whether assessed in accordance with expert's expertise - TORTS – negligence – dust diseases – causation – material contribution to injury, cumulative effect of exposure, reconciliation of cumulative effect of exposure with epidemiology - TORTS – negligence – dust diseases – duty of care – foreseeability – level of generality at which duty identified - TORTS – negligence – dust diseases – causation – relevant considerations - PROCEDURE – dust diseases – determining issues of general nature – Dust Diseases Tribunal Act 1998 (NSW), s 25B - WORKERS COMPENSATION – dust diseases – negligence – damages – domestic care and assistance – Workers Compensation Act 1987 (NSW), s 60AA Civil Liability Act 2002 (NSW), ss 3B, 5D Dust Diseases Tribunal Act 1998 (NSW), ss 25B, 32 Dust Diseases Tribunal Rules, r 9 LEGISLATION CITED: Evidence Act 1995 (NSW), ss 55, 79 Supreme Court Act 1970 (NSW), ss 69, 75A US Federal Rules of Evidence, r 702 Workers Compensation Act 1987 (NSW), ss 59, 60, 60AA CATEGORY: Principal judgment Adeels Palace Pty Ltd v Moubarak [2009] HCA 48; 239 CLR 420 Amaca Pty Ltd v Ellis [2010] HCA 5; 240 CLR 111 Australian Broadcasting Tribunal v Bond [1990] HCA 33; 170 CLR 321 Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139 Bonnington Castings Ltd v Wardlaw [1956] AC 613 Caltex Refineries (Qld) Pty Ltd v Stavar [2009] NSWCA 258; 75 NSWLR 649 Commissioner for Railways (Queensland) v Peters (1991) 24 NSWLR 407 Daubert v Merrell Dow Pharmaceuticals Inc 509 US 579 (1993) Downes v Amaca Pty Ltd [2010] NSWCA 76 Elliott v The Queen; Blessington v The Queen [2007] HCA 51; 234 CLR 38 EM Baldwin & Son Pty Ltd v Plane [1998] NSWCA 23; 17 NSWCCR 434 Frye v United States 54 App DC 46, 47; 293 F 1013 Goodwin v Commissioner of Police [2010] NSWCA 239 Graham Barclay Oysters Pty Ltd v Ryan [2002] HCA 54; 211 CLR 540 HG v The Queen [1999] HCA 2; 197 CLR 414 Malec v JC Hutton Pty Ltd [1990] HCA 20; 169 CLR 638 CASES CITED: McPherson's Ltd v Eaton [2005] NSWCA 435; 65 NSWLR 187 Minister for Immigration and Citizenship v SZMDS [2010] HCA 16; 240 CLR 611 Minister for Immigration and Multicultural and Indigenous Affairs v SGLB [2004] HCA 32; 78 ALJR 992 Mount Isa Mines Ltd v Pusey [1970] HCA 60; 125 CLR 383 R v Elliott; R v Blessington [2006] NSWCCA 305; 68 NSWLR 1; 164 A Crim R 208 R v Jamieson, Elliott and Blessington (1992) 60 A Crim R 68 R v Tang [2006] NSWCCA 167; 65 NSWLR 681 (Re Jones-Mashman) Amaca Pty Ltd v CSR Ltd (No 2) [2009] NSWDDT 24 Re Minister for Immigration and Multicultural Affairs; Ex parte Applicant S20/2002 [2003] HCA 30; 77 ALJR 1165 Seltsam Pty Ltd v McGuiness [2000] NSWCA 29; 49 NSWLR 262 Seltsam Pty Ltd v McNeill [2006] NSWCA 158; 4 DDCR 1 Sydney Water Corporation v Turano [2009] HCA 42; 239 CLR 51 Tabet v Gett [2010] HCA 12; 240 CLR 537 Vairy v Wyong Shire Council [2005] HCA 62; 223 CLR 422 Washer v Western Australia [2007] HCA 48; 234 CLR 492 Wiki v Atlantis Locations (NSW) Pty Ltd [2004] NSWCA 174; 60 NSWLR 127 Wyong Shire Council v Shirt [1980] HCA 12; 146 CLR 40 Aronson, Dyer and Groves, Judicial Review of Administrative Action (4th ed, 2009) at pp 820-825 "Complications of Asbestosis" (30 April 1960) British Medical Journal, p 1345 D L G Thomas "Pneumonokoniosis in Victorian Industry", 19 January 1957 Medical Journal of Australia, pp 75, 76 "Dust Hazard in Industry", in an Australian trade journal known as Manufacturing and Management, published 10 July 1956 Merewether and Price, United Kingdom, Home Office, Report on the Effects of Asbestos Dust on the Lungs and Dust Suppression in the Asbestos Industries (1930) TEXTS CITED: New South Wales Department of Public Health's Report of the Director-General of Public Health NSW, 1948 P.B.S. Fowler, J.C. Sloper, E.C. Warner, "Exposure to Asbestos and Mesothelioma of the Pleura", British Medical Journal, (25 July 1964), p 211 "Silicosis and Asbestosis: Memorandum on Industrial Diseases of Silicosis and Asbestosis" (October 1932), published in a journal known as The Quarry and Road Making, at p 420 Trindade, Cane and Lunney, The Law of Torts in Australia (4th ed, 2007) at p 554 United Kingdom Home Office's Annual Report of the Chief Inspector of Factories for the Year 1938 (July 1939), p 63 Victorian Government Gazette No 721, at 3965 2010/138836/001 - Summons: Amaba Pty Ltd (under NSW administered winding up) - Appellant Dust Diseases Tribunal - First Respondent John William Booth - Second Respondent Amaca Pty Ltd (under NSW administered winding up) - Third Respondent 2010/138836/002 - Appeal: Amaba Pty Ltd (under NSW administered winding up) - Appellant John William Booth - First Respondent Amaca Pty Ltd (under NSW administered winding up) - Second Respondent PARTIES: CA 2010/138880/001 – Summons: Amaca Pty Ltd (under NSW administered winding up) - Appellant Dust Diseases Tribunal - First Respondent John William Booth - Second Respondent Amaba Pty Ltd (under NSW administered winding up) - Third Respondent 2010/138880/002 - Appeal: Amaca Pty Ltd (under NSW administered winding up) - Appellant John William Booth - First Respondent Amaba Pty Ltd (under NSW administered winding up) - Second Respondent FILE NUMBER(S): CA 2010/138836; CA 2010/138880 G M Watson SC/J C Sheller (Amaba Pty Ltd/Amaca Pty Ltd) COUNSEL: Submitting appearance (Dust Diseases Tribunal) P Semmler QC/S Tzouganatos (John William Booth) DLA Phillips Fox (Amaba Pty Ltd) SOLICITORS: I V Knight, Crown Solicitors Office (Dust Diseases Tribunal) Holman Webb (Amaca Pty Ltd) Turner Freeman (John William Booth) LOWER COURT JURISDICTION: Dust Diseases Tribunal LOWER COURT FILE NUMBER(S): DDT 8212/2008 LOWER COURT JUDICIAL OFFICER: Curtis DCJ LOWER COURT DATE OF DECISION: 10 May 2010 LOWER COURT MEDIUM NEUTRAL CITATION: Booth v Amaca Pty Ltd [2010] NSWDDT 8 IN THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 2010/138836 CA 2010/138880 BEAZLEY JA GILES JA BASTEN JA 10 December 2010 AMABA PTY LTD (UNDER NSW ADMINISTERED WINDING UP) v John William BOOTH; AMACA PTY LTD (UNDER NSW ADMINISTERED WINDING UP) v John William BOOTH Headnote The respondent, John William Booth, suffers from mesothelioma, contracted from the inhalation of asbestos. His domestic and employment history suggests that he was exposed to asbestos in four periods. In a domestic context, Mr Booth was exposed to asbestos in his youth. Secondly, for a period of months in 1959, Mr Booth worked as a truck driver. Thirdly, Mr Booth was exposed to asbestos while working with brake linings as a motor mechanic for a period of nine years from 1953 until 1962. In that period he worked with brake linings containing asbestos manufactured by Amaca Pty Ltd ("Amaca"). Fourthly, between 1962 and 1982 (excluding a period from 1969 to 1971) the respondent worked as a brake mechanic and was exposed to asbestos in products produced by Amaba Pty Ltd ("Amaba"). The appellants were not the sole providers of brake linings during the respective periods, but the primary judge found that in each of the third and fourth periods, each company was responsible for 70% of the asbestos fibre to which Mr Booth was exposed. On 10 May 2007 Mr Booth obtained a judgment against the appellants in the amount of $326,640 in the Dust Diseases Tribunal ('the Tribunal'): Booth v Amaca Pty Ltd [2010] NSWDDT 8. Each of the appellants challenge virtually all of the findings made by the primary judge in respect of liability and a particular finding with respect to damages. The right of appeal is granted by s 32 of the Dust Diseases Tribunal Act 1998 (NSW) ("the Tribunal Act") to a party dissatisfied with a decision of the Tribunal in point of law or on a question as to the admission of evidence. Against the possibility that the grounds sought to be raised might not fall within the scope of that appeal right, the appellants also commenced proceedings in the original jurisdiction of the Court, pursuant to s 69 of the Supreme Court Act 1970 (NSW) seeking to have the judgment below set aside for error of law. The issues for determination on appeal in the Court were: (i) whether expert evidence called by the plaintiff should have been admitted; (ii) whether general and specific causation was established; (iii) whether the injury to the respondent was foreseeable; (iv) whether the appellants breached their duty of care; (v) whether a causal link was established between the breach of the duty of care and the injury suffered; (vi) whether the trial judge was correct in determining the question of causation for the purpose of other similar cases, pursuant to s 25B of the Tribunal Act; (vii) whether the trial judge was correct in awarding damages for domestic care and assistance. The Court held, dismissing the appeal: In relation to (i) 1. The admissibility of the expert evidence must be assessed in light of their expertise. The appellants' objection is resolved by addressing the contention that Professor Henderson failed to engage with the epidemiological evidence said to demonstrate that there was no causal link between exposure to asbestos in the course of undertaking brake repairs and mesothelioma. That proposition failed because it assumed that epidemiological evidence was both relevant and dispositive of, or at least superior to, direct evidence of causation. It also failed because Professor Henderson did not disregard the epidemiological evidence: [60]-[69]. In relation to (ii) 2. The respondent had to establish on the balance of probabilities that, in respect of each appellant, exposure to inhalation of asbestos liberated from its products materially contributed to his injury: [84]. 3. The evidence indicated that the incidence of mesothelioma increases in proportion to increased doses. Findings as to the cumulative effect of exposure to asbestos were undoubtedly open to the primary judge. The plaintiff's witnesses sought to reconcile that approach with the epidemiology that suggested there was no increased risk in the case of brake mechanics. It was open to the trial judge to accept that evidence, as he did. The underlying proposition put forward by the appellants, that the epidemiology was conclusive, did not give rise to a question of law, but to a question of fact, which the trial judge resolved against the appellants: [89]-[90]. Seltsam v McGuiness [2000] NSWCA 29; 49 NSWLR 262 distinguished. 4. The primary judge did not misapply the general law test of causation: [111]. Adeels Palace Pty Ltd v Moubarak [2009] HCA 48; 239 CLR 420; Amaca Pty Ltd v Ellis [2010] HCA 5; 240 CLR 111; Tabet v Gett [2010] HCA 12; 240 CLR 537 distinguished. 5. The appellants said the evidence relating to "biological process" whereby asbestos causes mesothelioma was "incapable" of supporting a finding in favour of the respondent. The biological process is "incompletely understood" but proof on the balance of probabilities permits a gap between complete understanding and sufficient understanding. The evidence distinguished between the risk and the event. The biological process postulated was not "undermined" by evidence that "not all of the asbestos was necessary to produce the outcome"; there were multiple contributing causes: [116]-[121]. 6. The complaint that the primary judge applied an incorrect legal test by finding that it was sufficient to establish general causation if science could not rule out a causal connection misread the judgment: [136]. In relation to (iii) 7. The finding of foreseeability was not made at too high a level of generality. Nor did the appellant successfully demonstrate an inadequacy of reasons by the trial judge's reference to "other documents in evidence to which I have not referred". If material to which the primary judge made reference was sufficient to allow the relevant inferences to be drawn, the fact that there was other material in evidence, supportive of those inferences, cannot assist on an appeal limited to a decision of the Tribunal in point of law: [168], [170]. 8. The trial judge correctly assessed the duty by reference to "motor mechanics working on brake linings", to a class of persons "regularly and cumulatively exposed to the inhalation of asbestos fibres released from asbestos products upon which they worked in an industrial setting" and specifically to mesothelioma. While factual findings may be made at a higher level of generality when dealing with duty, than when dealing with breach, the level of abstraction should not be such as to render the formulation of duty in terms which are "devoid of meaningful content". The question was whether the appellants, as manufacturers of products containing asbestos, owed a duty to take reasonable care in the manufacture and distribution of such products to workers who might be required to grind or otherwise manipulate the product in such a way as to release asbestos. Once it is known that release of asbestos dust causes a risk to health, the duty does not need to be defined more precisely. The trial judge was entitled to consider the facts by reference to asbestos-related disease, rather than the specific disease suffered by the respondent: [172]-[180]. Sydney Water Corporation v Turano [2009] HCA 42; 239 CLR 51; Vairy v Wyong Shire Council [2005] HCA 62; 223 CLR 422 applied. 9. While the evidence available in 1953 might not have demonstrated a significant risk to persons exposed to low levels of dust on rare occasions, the risk of exposure in an industrial setting where the exposure was likely to be encountered weekly, daily or more often, over months or years and the need to take precautions against the risk of serious injury was, by 1953, well-supported in the evidence: [188]. Seltsam Pty Ltd v McNeill [2006] NSWCA 158; 4 DDCR 1; McPherson's Ltd v Eaton [2005] NSWCA 435; 65 NSWLR 187; Caltex v Stavar [2009] NSWCA 258; 75 NSWLR 649 considered. 10. The negligence of the appellants was identified as the failure to give a warning. Whether or not such a warning should have accompanied brake linings depended on (a) whether it was reasonably foreseeable that those automotive mechanics responsible for removing and fitting brake linings would be exposed to asbestos dust and, (b) whether such exposure carried with it a risk to health. There is no complaint that the trial judge could not have found that it was reasonably foreseeable to both appellants that automotive mechanics undertaking the task would be exposed to asbestos dust. Accordingly, it was open to the trial judge to find that the risks to health were foreseeable on the basis of material which did not relate specifically to automotive mechanics: [192]. In relation to (iv) 11. In relation to breach, the relevant considerations included what, prospectively, would have been considered reasonable precautions by a person in the place of the appellants; an assessment of the nature and extent of the risk involved, including the magnitude of the risk and the gravity of the consequences if the risk materialised; and the costs of possible precautions. All of those factors were identified by the trial judge in his reasons and all were relevant in accordance with general law principles: [220]. Wyong Shire Council v Shirt [1980] HCA 12; 146 CLR 40 cited. 12. The proper content of an adequate warning; the terms of the warning which Amaba had adopted in 1978, which the trial judge considered inadequate; and the memorandum of May 1969, in which a director of Amaca proposed issuing a series of bulletins providing an entirely partisan view of the problem, were all permissible considerations. The failure to give a warning in terms which conformed to the Asbestos Research Council proposal of 1968 was deliberate and was a decision taken in full knowledge of the problems which had been identified by that time. There was no error of law in considering such factors: [225]. 13. The documents of 1969 and 1972 suggested that Amaba was, over many years, concerned that a realistic warning might have a significant, if not dramatic, effect on the market for its products. In considering what was a reasonable response of the company, it was legitimate to take into account those considerations. However, the trial judge was not bound by the assessment the company made of that response and was entitled to hold that its response was unreasonable and inadequate. His conclusion that the warning was entirely inadequate was open on the material before him: [227]. In relation to (v) 14. Amaba relied upon Mr Booth's evidence that he would have followed the warning used after 1978 if he had seen it. The trial judge concluded that the 1978 warning was not adequate because it was not in sufficiently graphic terms to arrest the attention of the reader and because it was not sufficiently visible. Thus, in respect of the actual warning, Mr Booth's evidence constituted a "concession" potentially in Amaba's favour; in respect of any better warning, it provided evidence of causation. The latter point was implicit in the trial judge's acceptance of the "concession" and the manner in which he dealt with it: [237]. In relation to (vi) 15. The determination made by the trial judge for the purpose of s 25B of the Tribunal Act did not purport to have any consequence for the present proceedings. The determination itself does not constitute a decision having legal force and effect and the determination did not find its way into the orders from which an appeal may be brought: [154]-[155]. In relation to (vii) 16. The primary judge did not err in law by failing to refer to s 60AA of the Workers Compensation Act 1987 (NSW), and thus the possibility of compensation being payable by the Dust Diseases Board, absent evidence that such an entitlement arose in the present case: [244]-[245]. IN THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 2010/138836 CA 2010/138880 BEAZLEY JA GILES JA BASTEN JA 10 December 2010 AMABA PTY LTD (UNDER NSW ADMINISTERED WINDING UP) v John William BOOTH; AMACA PTY LTD (UNDER NSW ADMINISTERED WINDING UP) v John William BOOTH Judgment 1 BEAZLEY JA: I agree with Basten JA. 2 GILES JA: I agree with Basten JA. 3 BASTEN JA: INDEX Paragraph Number (1) Brief factual background 7 (2) Issues 12 (3) Available grounds: error of law, no evidence and illogicality 20 (4) Admissibility of evidence 27 (a) epidemiological evidence 30 (b) quantification of exposure 34 (c) expert evidence for plaintiff 41 (d) notice of appeal: ground 3 71 (5) Grounds 1, 7, 8 and 10 – causation 80 (a) identification of legal test 84 (b) application of Seltsam: ground 1(b) 90 (c) application of Plane: ground 1(e) 91 (d) the "but for" test of causation: ground 8 93 (e) finding based on biology: grounds 7 and 10 115 (f) reversal of onus of proof: grounds 1(a) and (c) 136 (g) failure to give adequate reasons: ground 1(d) 143 (6) Findings under s 25B 148 (a) appeal: ground 11 148 (b) judicial review proceedings 157 (7) Duty of care: foreseeability - Amaca: ground 12 159 (8) Duty of care: foreseeability – Amaba: ground 12 189 (9) Duty of care – content of duty: grounds 13-15 204 (10) Breach of duty: ground 16 217 (11) Damages: ground 17 239 (12) Conclusions 246 4 The respondent, John William Booth, suffers from mesothelioma, contracted from the inhalation of asbestos. On 10 May 2010 he obtained a judgment against the present appellants in the amount of $326,640 plus costs in the Dust Diseases Tribunal: Booth v Amaca Pty Ltd [2010] NSWDDT 8 (Curtis DCJ). By notices of appeal dated 3 June 2010, each of the appellants challenge virtually all of the findings made by the primary judge in respect of liability and a particular finding with respect to damages. Because most of the grounds were the same in each appeal, unless otherwise indicated, references below will be to Amaca's amended notice of appeal. Not all the numbered or lettered grounds are referred to, as Amaca abandoned grounds 2, 4-6, 9 and also abandoned the particulars in ground 14. Most appeal grounds were similar in content to Amaba's appeal grounds. 5 The right of appeal is granted by s 32 of the Dust Diseases Tribunal Act 1998 (NSW) ("the Tribunal Act") to a party dissatisfied with a decision of the Tribunal in point of law or on a question as to the admission of evidence. Against the possibility that the grounds sought to be raised might not fall within the scope of that appeal right, the appellants also commenced proceedings in the original jurisdiction of the Court, pursuant to s 69 of the Supreme Court Act 1970 (NSW) seeking to have the judgment below set aside for error of law. 6 The appellants have failed to establish that his Honour erred in law and the appeals should be dismissed. No separate argument was presented in relation to errors which might engage an entitlement to relief in the nature of certiorari and each summons must also be dismissed. (1) Brief factual background 7 Mr Booth was diagnosed with mesothelioma in June 2008. He was 71 years of age. It was not in dispute that the disease was caused by the inhalation of asbestos. His domestic and employment history suggests that he was exposed to asbestos in three contexts. 8 First, there were two incidents of domestic exposure in his youth. On one occasion in 1943, when he was about 8 years old, his father built a two bedroom house and boatshed at Lugarno. Although he said that he was generally sent off to play, to get him out of the road, on a number of occasions he held asbestos sheeting down whilst his father used fibro cutters. On a second occasion, about 10 years later, he helped his father build a fibro garage at Peakhurst. The work occupied two days and the work with fibro sheeting one day: at [7] in judgment below. Three sheets were cut for doors and windows, again by his father whilst he held the sheets in place. It was not suggested that any exposure to asbestos dust in the course of those activities gave rise to any legal liability on the part of either appellant. 9 Secondly, for a period of months in 1959, Mr Booth worked as a truck driver. On one day, he spent 20 minutes helping to load bags of asbestos at the Sydney wharves. He drove the truck to a factory where it was unloaded by others: at [9]. Again, the exposure was not relied upon as part of the responsibility of either appellant. Rather, the appellants relied on each of these non-tortious exposures as potential causes of his mesothelioma. 10 Thirdly, he was exposed to asbestos dust while working with brake linings as a motor mechanic. For a period of nine years from 1953 until 1962 he worked with brake linings containing asbestos manufactured by Amaca Pty Ltd ("Amaca"). Between 1962 and 1983 (excluding the period from 1969 to mid-1971 when he was doing other work) he worked for a further period as a brake mechanic and was exposed to asbestos in products produced by Amaba Pty Ltd ("Amaba"): at [163]. Each period of work as a motor mechanic was relied upon as giving rise to liability on the part of each appellant respectively. 11 The appellants were not the sole providers of brake linings during the respective periods, but the primary judge found that in each relevant period, those companies were responsible for 70% of the asbestos fibre to which Mr Booth was exposed: at [165]. (2) Issues 12 There were two main issues addressed by the appellants, both at trial and in this Court. They were the foreseeability of injury to the respondent and the establishment of a causal link between any tortious exposure and the injury suffered. Both at trial and in this Court, those issues were addressed in the reverse order and it will be convenient to deal with causation before duty of care. 13 The complaints on appeal in relation to duty of care were not limited to the foreseeability of injury at specific times, but included a complaint that the trial judge had failed to determine the content of any duty which might have been owed at a particular point in time. In addition, though the argument on this point was largely consequential upon the earlier arguments, the appellants asserted that there had been no breach of any duty which existed. 14 A severable complaint concerned the statement by the trial judge that he was determining the question of causation for the purpose of other similar cases generally, pursuant to s 25B of the Tribunal Act. If that were a misconception as to his Honour's powers, it was not one which affected the outcome in the present case. 15 Finally, there was a challenge to the assessment of damages, limited to the amount allowed in respect of domestic care and assistance. 16 Before turning to the substantive grounds of appeal, it is convenient to note the matters which were not in dispute and the primary issues identified in respect of the medical evidence. His Honour noted at [22]: "The following matters are not in dispute: (1) The plaintiff's mesothelioma was caused by the inhalation of asbestos fibre. (2) Chrysotile asbestos has the capacity to cause mesothelioma. (3) The brake linings manufactured by the defendants contained chrysotile asbestos. (4) Mr Booth inhaled chrysotile asbestos fibres liberated from the defendants' products." 17 His Honour then identified the case presented before him on behalf of the plaintiff in the following terms: "23 The plaintiff relies upon the expert medical opinions of Professor Douglas Henderson, Dr James Leigh, Dr Morris Heiner, and Professor William Musk, that all exposure to asbestos within an acceptable latency period materially contributes to the mesothelioma in a particular individual, and that Mr Booth's exposure to chrysotile in the course of his work as a mechanic materially contributed to the cause of his disease. 24 Professor Henderson, Dr Heiner and Professor Musk have each experienced cases of mesothelioma in their respective practices where the only identified exposure derived from working with brake linings." 18 After briefly noting the opinions expressed by the four medical experts called on behalf of Mr Booth, his Honour identified the principal arguments relied on by the defendants at [39]: "(1) Because the biological process whereby the inhaling of asbestos causes mesothelioma is incompletely understood, medical science cannot support the proposition advanced by the plaintiff's expert witnesses that all asbestos inhaled materially contributes to the causes of mesothelioma. Such expressions of opinion are inadmissible because they are not based upon that which is ' recognised to be accepted as a reliable body of knowledge' ( HG v The Queen (1999) 197 CLR 414 per Gaudron J at [58]). (2) It is highly unlikely that Mr Booth's work on brake linings caused his mesothelioma because: (a) chrysotile is unlikely to produce mesothelioma, (b) brake linings contain resins which adhere to the chrysotile fibres rendering them non-respirable, (c) the handling of brake parts produces asbestos fibres so short that they are harmless, and (d) the number of chrysotile fibres produced by the handling processes are so few that the effect is harmless. (3) The only epidemiological studies admitted into evidence demonstrate that brake work does not increase the risk of mesothelioma. (4) When quantified, Mr Booth's cumulative exposure to the products of either Amaca or Amaba is insignificant in comparison to his background and other exposures, and made no material contribution to the causes of his mesothelioma." 19 The respondent submitted that the issues so identified, with the exception of the challenge to the admissibility of the expert evidence, were primarily, if not entirely, matters of fact. If the evidence were admitted, no issue of law would arise, unless it could be said that the evidence of Mr Booth's experts was incapable of supporting the findings giving rise to liability. Further, the respondent submitted that it was not open to the appellants to attack the reasoning process as being "marred by patent error, illogicality or perversity". It is convenient to deal with the legal principles first and then turn to the question of the admission of the expert evidence. (3) Available grounds: error of law, no evidence and illogicality 20 Subject to one qualification, because the appellants invoked the supervisory jurisdiction of the Court, as well as their right of appeal under s 32 of the Tribunal Act, it is not necessary to consider in detail the limitations on the statutory right of appeal. It will be sufficient for present purposes to assume that the appellants are entitled to the intervention of this Court if they can establish a material error of law on the part of a trial judge. The qualification concerns the potentially greater width of the challenge available under s 32 in relation to a decision of the Tribunal "on a question as to the admission or rejection of evidence". Although the matter was not addressed in submissions, it may be assumed for present purposes (in favour of the appellants) that the challenge to the admission of evidence is not restricted to legal error, but invokes the powers of this Court on a rehearing, pursuant to s 75A of the Supreme Court Act. 21 That question aside, it is necessary to address the respondent's argument that, once the medical evidence tendered on behalf of Mr Booth is held to be properly admitted, it will not be open to the appellants to challenge findings based on that evidence because it will be impossible for them to say that there was no evidence capable of supporting the findings of the trial judge. In accordance with statements by Glass JA (Samuels JA agreeing) in this Court in Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139 and the statement of Mason CJ in Australian Broadcasting Tribunal v Bond [1990] HCA 33; 170 CLR 321 it was submitted that no broader claim is permitted. As explained by Mason CJ at 356: "Thus, at common law, according to the Australian authorities, want of logic is not synonymous with error of law. So long as there is some basis for an inference – in other words, the particular inference is reasonably open – even if that inference appears to have been drawn as a result of illogical reasoning, there is no place for judicial review because no error of law has taken place." 22 However, as I noted recently in Goodwin v Commissioner of Police [2010] NSWCA 239 at [12], some doubt has been cast on the scope and operation of that principle by reference in later judgments to the need for findings or inferences of fact to be supported by "logical grounds": see Re Minister for Immigration and Multicultural Affairs; Ex parte Applicant S20/2002 [2003] HCA 30; 77 ALJR 1165 at [52] (McHugh and Gummow JJ, Callinan J agreeing); Minister for Immigration and Multicultural and Indigenous Affairs v SGLB [2004] HCA 32; 78 ALJR 992 at [38] (Gummow and Hayne JJ); Minister for Immigration and Citizenship v SZMDS [2010] HCA 16; 240 CLR 611 at [40] (Gummow and Kiefel JJ, dissenting); cf [113], [119] and [129]-[130] (Crennan and Bell JJ). 23 Implicit in the statement that there is no evidence to "support" a particular finding, is the characterisation of a relationship between the evidence and the finding. It is the same relationship inherent in the concept of "relevance", on which the laws of evidence depend. That relationship depends on a process of reasoning which must be logical or rational. Thus, evidence is relevant which, if accepted, "could rationally affect (directly or indirectly) the assessment of the probability of the existence of a fact in issue in the proceeding": Evidence Act 1995 (NSW), s 55(1). As explained by Gleeson CJ, Heydon and Crennan JJ in Washer v Western Australia [2007] HCA 48; 234 CLR 492 at [5]: "The word 'rationally' is significant in this context. In order to establish relevance, it is necessary to point to a process of reasoning by which the information in question could affect the jury's assessment of the probability of the existence of a fact in issue at the trial." 24 Whether an inference is reasonably open, in the sense of being logically available, involves an evaluative judgment, which is to be assessed by the court exercising appellate or supervisory jurisdiction. 25 Although it appears not to have been addressed in these terms, it seems that the reviewing court should make its assessment, based on findings of primary fact made by the trial judge, as an exercise of its own judgment, rather than by analysing the cogency of the reasons given by the primary judge. This point may be significant, depending upon whether the challenge is directed to inferences drawn from primary facts, or to the findings of primary facts themselves, which are said not to be supported by the evidence. As a practical matter, of course, it is neither appropriate nor necessary to disregard the reasons given by the primary judge for reaching a particular conclusion. 26 These issues were not addressed in the course of the appeal, but it is convenient to assume that illogicality, in the sense noted at [23] above, can be relied upon by the appellants as a basis of challenge to facts found or inferences drawn by the primary judge, as demonstrating error of law. (4) Admissibility of evidence 27 In order to understand the submissions in respect of this challenge, it is necessary to place the evidence in the broader context of the submissions as to causation. 28 The case for the appellants (the defendants at trial) relied upon two separate, but complementary, propositions. The first was that epidemiological studies showed that there was no increased incidence of mesothelioma amongst motor mechanics. Secondly, based on reconstructions of the plaintiff's exposure to asbestos dust at various times in his life, the defendants argued that, compared with other causative factors, the chance that the exposure to asbestos dust, created by their products, caused the mesothelioma, was less than 50% and therefore did not satisfy the test of being more probable than not. 29 At least at a factual level, it was necessary that the trial judge weigh the epidemiological studies together with the medical evidence called by the plaintiff, which asserted that all exposure contributed to the mesothelioma, and to evaluate from the evidence the contribution of the plaintiff's exposure to asbestos dust created by each of the appellants' products to his mesothelioma. (a) epidemiological evidence 30 His Honour accepted the proposition that epidemiological studies demonstrated that exposure to chrysotile asbestos increases the likelihood of contracting mesothelioma: at [67]. That, he noted, was conceded: at [68]. That conclusion was to be contrasted with a series of studies which, as analysed in combination, suggested there was "no evidence to support … an association between increased risk of mesothelioma and exposure to brake linings": at [71], [72] and [73]. 31 His Honour did not accept the last conclusion, so broadly stated. He noted that the groups of workers studied were variously described as "motor mechanics", "garage workers" and "vehicle mechanics", noting that individuals within those groups may or may not have been exposed to asbestos fibres and may have had little in common with the evidence of exposure of the plaintiff: at [75]. His Honour also referred to the limited inferences which could be drawn from the studies: at [76]-[80]. He noted that Dr Leigh, who had training in epidemiology, argued that "much of the data does support a strong correlation between exposure to asbestos as an auto mechanic and the contraction of mesothelioma": at [81]. His Honour referred to the written submissions in support of that proposition but did not "canvass his evidence on this matter": at [81]. This gave rise to a complaint of a failure to give reasons for his decision, which will be addressed below. 32 At [82] his Honour concluded: "I am not persuaded that the epidemiological evidence specific to automotive mechanics is adverse to the submission that causation has been proved in this particular case." 33 This last proposition was said to involve a reversal of the onus of proof, although it was clearly intended to reject the defendant's submission that this evidence cast doubt upon the affirmative evidence of the plaintiff's expert. Those criticisms will need to be addressed, but the finding itself neither could be, nor was, challenged on the appeal. (b) quantification of exposure 34 At trial, the defendants sought to quantify each of the known elements of exposure to asbestos dust in the plaintiff's life. To do so, they called evidence from two occupational hygienists, Messrs Pickford and Rogers. In particular, they sought to identify the level of exposure in the course of home renovations and loading of trucks, on the one hand, which they compared with the likely level in the course of brake repairs. The results were then given to Professor Berry, an epidemiologist, to assess the relative risk resulting from exposure in the course of repairing brakes, compared with all other exposures. 35 This exercise depended upon the reliability of the estimates of exposure, none of which had been measured and all of which were essentially based on speculation. His Honour noted elements of disparity, stating at [96]: "In the present case Mr Pickford's estimate of home renovation exposure was nearly double that of Mr Rogers. His initial estimate of the exposure loading trucks, on similar assumptions, was 11 times greater than that of Mr Rogers. These differences do not engender confidence in the accuracy or utility of the exercise." 36 His Honour referred to the comments of Professor Berry who noted that he had, in other cases, "seen widely differing estimates of cumulative exposure from occupational hygienists, and that 'sometimes there are differences of say tenfold'": at [95]. His Honour was critical of specific aspects of the evidence of each witness. In respect of Mr Rogers, the trial judge concluded at [153]: "With the exception of his estimate of the fibre concentration to which Mr Booth was exposed when loading hessian bags of asbestos onto his truck, I reject the evidence of Mr Rogers. I am unpersuaded that his assumptions and methods fairly reflect the circumstances in which Mr Booth was exposed to the inhalation of asbestos fibre." 37 In relation to Mr Pickford's evidence, his Honour reached the following conclusions: "134 Upon the assumption that the asbestos in the home renovations was amosite, the combined lifetime risk created by the accumulation of brake exposure, home renovations, and loading trucks with chrysotile was 31.4 per million. Of this risk, the brake repair work contributed 97 per cent. 135 Upon the assumption that the asbestos in the home renovations was crocidolite, the combined lifetime risk created by this accumulation of exposures was 35 per million. Of this risk the brake repair work contributed 87 per cent. 136 Professor Berry says that it may be appropriate to assume that the background exposure of Mr Booth to asbestos fibre as a consequence of general low-level concentrations of asbestos in urban air corresponds to a lifetime risk of 70 per million. 137 The brake repair work increased the background causal component of 70 per million lifetime risks by a further 30.6 per million lifetime risks. Expressed in terms of cause, the brake work increased by approximately 44 per cent that fibre burden which comprised the background risk. 138 I regard such a contribution as material. 139 Even if the background risk was 170 per million lifetime risks, Professor Berry's upper limit, the contribution from the brake work remains material." 38 In short, his Honour dismissed the fourth argument relied upon by the defendants, namely that their contribution to the asbestos exposure suffered by the plaintiff was insignificant. His Honour was satisfied that the evidence established that it was "material". 39 These conclusions were also relevant to his Honour's rejection of the second set of arguments, relying upon the improbability that exposure through work on brake linings caused mesothelioma. His Honour dealt with the second set of arguments at [63]-[66] and no specific complaint was made about these findings. 40 The admissibility of the expert evidence went to the first argument upon which the defendants relied, challenging the assertions of the plaintiff's experts that all asbestos inhaled materially contributed to the mesothelioma. (c) expert evidence for plaintiff 41 The ground of appeal relied upon in respect of the admission of evidence treated the evidence as having been proffered "on the issue of general causation": ground 3. That language was also used in asserting that the trial judge had erred in point of law in deciding that the plaintiff "established general causation – ie that asbestos inhaled during the course of the plaintiff's work could cause his injury": ground 1. Grounds 7 and 8 were headed "Specific causation", but did not purport to define that phrase. Ground 10 is also relevant in this context and read: "The trial judge erred in point of law by finding (if he did) that causation was established by some understanding of a biological process. Particulars (a) The evidence was incapable of supporting causation through a biological process." 42 In Amaca's written submissions, the issue described as "general causation" was identified as "whether handling brake components in the course of working as a motor mechanic can cause mesothelioma": written submissions for Amaca, par 15. 43 Although Amaba identified similar concepts in its grounds of appeal, it made no separate submissions in respect of "general causation", but adopted Amaca's submissions in this respect. 44 A distinction between general and specific causation appears to derive from epidemiological usage, referred to by Spigelman CJ in Seltsam Pty Ltd v McGuiness [2000] NSWCA 29; 49 NSWLR 262 at [22], in the following passage: "The first question – Is the agent capable of causing the disease? – is sometimes referred to by epidemiologists as 'general causation'. The second question – Did the agent cause the disease in this case? – is sometimes referred to as 'specific causation'. Epidemiological evidence – both the statistics and the interpretation – may play a role with respect to both questions. For legal purposes, the relevant question is the second." 45 General causation as identified by the appellants did not conform with this usage. As counsel for the respondent correctly pointed out, general causation according to epidemiological usage did not provide a live issue in the present case. There was no dispute that the inhalation of asbestos dust caused mesothelioma and, indeed, was the sole cause of such a disease. 46 Even on the notion of general causation identified by the appellants, the grounds of appeal were misconceived. There was no question of whether handling brake components in the course of working as a motor mechanic could cause mesothelioma. The real question was whether the evidence was capable of supporting the finding that the inhalation of asbestos dust released from products manufactured by the each appellant caused the mesothelioma from which the respondent suffers. 47 The answer to that question depended upon whether there was evidence that all non-trivial exposures to asbestos dust materially contributed to the injury. If there were such evidence, the appellants must fail on their principal ground of appeal in relation to causation. 48 As noted above, the trial judge accepted the evidence of four experts called by the plaintiff. 49 For the present it is sufficient to refer to the evidence of Professor Henderson, because Amaca's written submissions (the issue not being separately addressed by Amaba) focused on his evidence: written submissions, par 38. The oral argument also dealt with the objection taken in respect of the evidence of Professor Henderson. As will appear, the relevant ground of appeal did not extend to Professor Henderson's evidence, although an earlier version of the ground of appeal probably did. It is appropriate to deal with the matter even if it was not properly subject to a ground of appeal. 50 Professor Henderson referred to the "Peto Model" named after one of its originators, which related risk of mesothelioma to the cumulative exposure to asbestos: Report of 2 March 2009, Appendix A, "The Scientific/Medical Evidence for Causation of Malignant Mesothelioma by Asbestos: The No-Threshold Dose-Response Model" (January 2009, p 2). Professor Henderson noted that one factor which emerged from the model was that "when there are multiple asbestos exposures, each contributes to cumulative exposure and hence to the risk and causation of mesothelioma, within an appropriate latency interval". In his oral evidence, Professor Henderson was asked to expand upon that statement and responded as follows (Tcpt, 23/02/10, p 95): "Well it goes to the issue of the dose-response model for mesothelioma induction by asbestos and that is that when there are multiple episodes of asbestos exposure and the individual concerned inhales increasing numbers of fibres on different occasions, that contributes to the total burden of asbestos fibres deposited in the lung and translocated to the pleura and it is thought that mesothelioma develops because of an interaction between the asbestos fibres and the mesothelial cells by way of secondary chemical messengers and to simplify the answer, the point is that the more fibres there are the greater number of fibres there will be interacting with mesothelial cells which themselves undergo proliferation and so the progress goes on with increasing numbers of mesothelial cells interacting with increasing numbers of fibres, so that the ultimate development of mesothelioma and its probability of development will be influenced by the number of fibres interacting with mesothelial cells over multiple periods of time and probably over multiple different generations of mesothelial cells and I think this is a fairly well accepted model now and it flies in the face of what used to be called the one fibre hypothesis that mesothelioma came about from a single fibre interacting with a single mesothelial cell which in biological terms is a ridiculous proposition." 51 Professor Henderson also stated (Tcpt, p 90): "It is, I think, almost universally accepted that all asbestos exposures, both recalled and unrecalled, will contribute causally towards the ultimate development of a mesothelioma." 52 This evidence was identified by his Honour at [25]-[26]. If it were properly admitted and accepted, it provided a basis for the conclusion that all exposure (and, by inference, inhalation) contributed to the mesothelioma suffered by the plaintiff. The immediate question is whether it should have been admitted. 53 That the objection was taken (and repeated) before the trial judge is not in doubt; what is less clear is the precise basis of the objection. The transcript suggested that the appellants' premise was that the only soundly based science in relation to the question of causation was to be found in the leading epidemiological studies relating to brake workers: Tcpt, 22/02/10, pp 77-78. In their written submissions in this Court, the appellants relied upon the objection as explained in the written submissions at the conclusion of the hearing below. It is convenient to deal with those submissions, as reflected in his Honour's statement of the issues, rather than by reference to the transcript. 54 In Amaca's written submissions at trial, dated 16 April 2010, the following appeared: "65. An opinion despite the scientific evidence or despite the absence of scientific evidence is not expert evidence. Expert evidence must be based upon that which is 'recognised to be accepted as a reliable body of knowledge': HG v The Queen … at [58], Velevski v The Queen (2002) 76 ALJR 402 per Gaudron J at [82], Gummow and Callinan JJ at [145]. 66. It is essential that the expert identify the expertise which could be brought to bear: HG v The Queen per Gleeson CJ at [40]. Here the 'specialised knowledge' is no more than a bare assertion – none of the experts has carried out original research. This is not 'specialised knowledge' ; it is an attempt to 'venture "opinions", (sometimes merely their own inference of fact), outside their specialised field of knowledge' and which 'may invest those opinions with a spurious appearance of authority, and legitimate process of fact-finding may be subverted' : HG v The Queen per Gleeson CJ at [44]; Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 at [59]-[87]. 67. Even if expert opinion evidence on general causation is admissible, it must be given no weight. It is not science; it is a belief held contrary to scientific knowledge. Those who hold the opinion must explain why no epidemiological study has ever demonstrated an increase of risk for mesothelioma. They did not do so." 55 Reliance was expressly placed upon the principles stated by the US Supreme Court in Daubert v Merrell Dow Pharmaceuticals Inc 509 US 579 (1993). The reference to Daubert requires some explanation. It involved a civil claim with respect to serious birth defects said to have been caused by the mother's ingestion of Bendectin, a prescription anti-nausea drug marketed by Merrell Dow. Merrell Dow sought to strike the proceedings out on the basis that there was no admissible evidence available to support the necessary conclusion of causation. Merrell Dow presented testimony from an expert establishing that no study undertaken of birth defects had found Bendectin to cause malformation in human foetuses. 56 The first step taken in Daubert was to abandon an existing test under Frye v United States 54 App DC 46, 47; 293 F 1013, 1014 (1923). Frye had rejected evidence provided by "a crude precursor to the polygraph machine": Daubert at 585. Frye permitted the introduction of evidence where "the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs": at 586. That test was held in Daubert to be inconsistent with the US Federal Rules of Evidence. The second step in Daubert was to identify an appropriate test, based on r 702. The Supreme Court derived its principles from that part of r 702 which required that the evidence "assist the trier of fact to understand the evidence or to determine a fact in issue". That proposition, the Court held, required a preliminary assessment of whether the reasoning or methodology underlying the testimony was "scientifically valid". Whilst insisting that the inquiry should remain a flexible one, (at 592-593), the Court outlined some factors which should ordinarily be addressed, including: (a) whether the theory or technique will be or has been tested – at 593; (b) whether the theory or technique has been subjected to peer review and publication, said to be a relevant, though not dispositive, consideration – at 593-594; (c) the known or potential error rate – at 594, and (d) whether the technique or theory attracts widespread acceptance in the relevant scientific community, absent which it may be viewed with scepticism – at 594. 57 However, the admissibility of expert opinion evidence is governed by s 79 of the Evidence Act. It requires that a person have 'specialised knowledge' and that the opinion proffered be 'wholly or substantially based on that knowledge'. This is not the same as r 702. The factors outlined by the US Supreme Court can only be of assistance, if at all, in determining whether the putative expert has specialized knowledge or whether the opinion is wholly or substantially based on that knowledge (see R v Tang [2006] NSWCCA 167; 65 NSWLR 681 at [139] per Spigelman CJ). The great variety in expert evidence which may be proffered at a trial, taken together with the circumstances in which it is proffered, should give rise to caution in imposing statements from case law, particularly case law with a different basis, on the application of a relatively straightforward statutory rule. 58 Secondly, the application of s 79 may require emphasis to be placed on different matters, depending upon the kind of expert evidence proffered. 59 Thirdly, statements in other cases must be understood in the context in which they were made. The remarks of Gleeson CJ in HG v The Queen [1999] HCA 2; 197 CLR 414 at [44] as to the risk of investing an opinion with "a spurious appearance of authority" must be understood in the light of a distinction being drawn between the kinds of opinion a psychologist could properly present in relation to prior sexual abuse of a child and an opinion based on "a combination of speculation, inference, personal and second-hand views as to the credibility of the complainant, and a process of reasoning which went well beyond the field of expertise of a psychologist": at [41]. 60 In the present case, the admissibility of Professor Henderson's evidence must be assessed in the light of his expertise. Although there was no challenge to his expertise, nor was there any reference to it in the submissions. It is convenient to note that Professor Henderson is identified in his report of 25 March 2009 as Professor of Pathology and Senior Consultant in Anatomical Pathology. In addition to holding a chair at Flinders University, South Australia, he is an internationally recognised expert on pleural tumours and mesothelioma. He has written extensively on asbestos-related diseases, was an author of the Helsinki Criteria for the Individual Attribution of Asbestos Related Disease (first published in 1997) and was an expert adviser to the Disputes Resolution Panel of the World Trade Organisation with respect to measures concerning asbestos products. 61 Nor was there any attempt in the submissions in this Court to identify an opinion expressed by Professor Henderson which was outside his area of expertise. As appears from the statement set out above, Professor Henderson expressed his statements as being "almost universally accepted". If it were to be suggested that an opinion he expressed was not widely accepted in the scientific community concerned with the causes of mesothelioma, it might have been expected that the appellants would tender evidence to support such a conclusion. No such evidence was proffered. 62 The objection must ultimately be resolved by reference to the contention that Professor Henderson failed to engage with the epidemiological evidence said to demonstrate that there was no causal link between exposure to asbestos in the course of undertaking brake repairs and mesothelioma. That proposition, however, fails at two levels. First, it fails because it assumed that epidemiological evidence is both relevant and dispositive of, or at least superior to, other evidence of causation. Secondly, it fails because Professor Henderson did not disregard the epidemiology. 63 The role of epidemiology in causation inquiries was explained by Spigelman CJ in Seltsam Pty Ltd v McGuiness at [93] in the following terms: "With respect to many diseases, medical science is able to give clear and direct evidence of a causal relationship between a particular act or omission and a specific injury or disease. There are, however, fields of inquiry where medical science is not able to give evidence of that character. There are cases in which medical science cannot identify the biological or pathological mechanisms by which disease develops. In some cases medical science cannot determine the existence of a causal relationship. Such a state of affairs is not necessarily determinative of the existence or non-existence of a causal relationship for purposes of attributing legal responsibility. Epidemiological evidence may be able to fill the gap. It is of particular potential utility in the field of what is often referred to as 'toxic torts', especially in case of diseases with long latency periods." 64 Professor Henderson's evidence in terms supported a causal relationship; accordingly, the epidemiological evidence was not essential or dispositive. 65 In submissions in this Court, Amaca stated that "clinical observations could not assist in this kind of case" and that the "only reliable scientific evidence in respect of causation is epidemiological evidence": written submissions, par 38. 66 On the ordinary understanding of clinical observations, the first statement is correct; but the second statement is belied by the evidence of Professor Henderson, with his undoubted expertise. And Professor Henderson did address the epidemiology. 67 Professor Henderson's principal report dated 2 March 2009 ran to some 24 pages, excluding footnotes and appendices. The first 14 pages identified in careful detail the background material upon which he was invited to express an opinion. He then set out the assumptions he had made in preparing the report: pp 14-15. 68 Professor Henderson addressed (pp 17-18) the question "Does chrysotile have the capacity to cause malignant mesothelioma?" He answered this question in the affirmative. He noted that his assessment was based on a number of factors, including studies in other countries. The second bullet point in his tabulation of the factors commenced "[i]n addition to the epidemiological evidence, experimental studies indicate …". 69 Professor Henderson discussed (p 19) the question "Does exposure to dust derived from brake linings that contain chrysotile asbestos have the capacity to induce mesothelioma?" He noted that the issue was specifically addressed in appendix B to his report, and referred to some of the studies. He stated in the following paragraph that "those reports focus almost exclusively on epidemiological studies on motor vehicle mechanics and essentially they omit studies on the toxicology and experimental models on the induction of mesothelioma by chrysotile …". Professor Henderson also noted that the reports omitted "any reference to the numbers of mesotheliomas recorded in the Australian Mesothelioma Register (AMR), related to dust exposures from work with brake linings …". His reference to the AMR, in appendix B at p 12, included the following: "Data in Australian Mesothelioma Register – which records all mesotheliomas in a nation of around 20,000,000 people – arguably constitute the strongest evidence for an increased risk of mesothelioma among brake mechanics who ground and chamfered new brake pads/linings/blocks. The AMR figures indicate that there is an increased risk of mesothelioma among brake mechanics: the AMR Report for 2002 lists 59 cases of mesothelioma for the exposure category brake linings – made/repaired (single exposure only) and a further 19 cases for the same class of exposure but with multiple patterns of exposure, giving a total of 78 cases. … Taking into account census data for automotive mechanics in Australia, it has been estimated that brake mechanics are at increased risk of mesothelioma, perhaps in the order of at least 20 cases per million person-years … (ie, a risk that is up to twenty fold greater than the 'background' risk of mesothelioma)." Professor Henderson then referred to and discussed a recent paper in which those conclusions were challenged. 70 The objections identified so far in relation to Professor Henderson's evidence are without merit. (d) notice of appeal: ground 3 71 The amended notice of appeal, filed during the hearing in this Court, was in somewhat different terms from the original notice of appeal. The amended ground 3 read as follows: "3. The Trial Judge erred in law in admitting and relying upon evidence as 'expert opinion evidence' on the issue of general causation (see judgment [76]-[78]). Particulars (a) The trial judge wrongly admitted and relied upon that evidence as 'expert opinion evidence'; (b) Although the trial judge noted an objection, he did not explicitly rule on the objections, address the defendants' submissions, or give reasons as to why the evidence could or should be admitted." 72 The expert evidence referred to in the judgment, at [76]-[78], was concerned with a different expert called by the respondent, Dr James Leigh. The paragraphs appear under the heading "Epidemiological evidence", which commenced at [67] with a discussion of the epidemiological studies relating to the incidence of mesothelioma in automotive mechanics, noted at [30]-[31] above. The discussion continued: "76. Dr Leigh, who is trained in epidemiology, gave cogent evidence criticising many of these studies upon the basis of weak case reference design, and low statistical power. He said that the standard text by Breslow and Day … required a power of 80 per cent before a study may be declared negative, and that none of the studies upon which the defendants rely achieved that power. 77. Specifically the power of the study by Welsh to detect a relative risk of 1.5 was 9 per cent. … 78. At a relative risk of 1.2, for every 10 persons who may contract mesothelioma from background risks, an additional 2 will contract the disease because of occupational exposure as an automotive mechanic. The statement by Wong that: there is no evidence to support or even to suggest an association between an increased risk of mesothelioma and exposure to brake linings is correct but misleading." 73 Where Dr Leigh gave this evidence and where the objection to it was to be found was never revealed to the Court. Well into the first afternoon of the appeal, senior counsel for the appellants was invited to identify by way of a list each objection to evidence and explain how it fell within the notice of appeal. Although the particular ground of appeal had not changed in its reference to pars [76]-[78] since it was filed on 3 June 2010, counsel was unable to undertake that task immediately. Shortly thereafter, however, he identified "an example" which was an objection taken to the evidence of Professor Henderson at Tcpt, pp 77-78, discussed at [53] above. 74 At no stage in either oral or written submissions did the appellants identify the evidence of Dr Leigh referred to in the judgment at [76]-[78]. On the second day of the hearing, in response to questions asked from the Bench, counsel produced a schedule of 15 objections taken to the evidence of Professor Henderson and Dr Leigh. So far as objection was taken to specific comments by Dr Leigh on epidemiological evidence, they were identified in the list provided by the appellants as an objection "in respect of inability of epidemiology to show small risks", referring to Dr Leigh's report of 5 February 2009, p 6: "However, it should be pointed out that inability to demonstrate epidemiologically a statistically significant increase in risk in an occupational category of work, relative to all other occupational categories does not negate in any way a causal inference in an individual case where the only asbestos exposure, above general background environment, was incurred in that occupation." 75 Taken out of context, that evidence does not appear to be the basis of his Honour's remarks at [76]-[78]. Rather, in a passage at the beginning of the same page of the report (p 6) Dr Leigh referred to the epidemiological studies as being "of weak case referent design and low statistical power". That language was the subject of explication in oral evidence: Tcpt, 26/02/10, p 235 ff. (The reference to Breslow and Day appears at p 241.) 76 In the schedule of objections, the objections taken to this additional evidence commenting on epidemiology were said to be based on the fact that the evidence was "not peer reviewed, nor in report": objection 15. That objection was in fact rejected on the basis Dr Leigh was being asked to comment upon a document tendered by the appellants: Tcpt, p 237. 77 Apart from the comments in the schedule, no submissions were put as to why this evidence should not have been admitted. The objection taken to the subsequent paragraph in the report in respect of the epidemiology was, somewhat curiously, described as "the Daubert point". The point appears to have been encapsulated at trial in the following explanation (Tcpt, 25/2/10, p 154): "[ Seltsam v ] McGuiness says, so we submit, that one needs to have a scientific basis for the assertion that exposure X causes outcome Y. And how that is to be determined, according to McGuiness , is to look at the epidemiology, if that's the best available evidence – and, pausing there, that's the only evidence in this case – is to look at the epidemiology and see whether it satisfies certain scientific and then legal tests. Scientifically, the epidemiology will satisfy a test if, for example, it's published in peer review literature and has been the subject of examination, potential analysis and testing by the scientific community. … As Your Honour knows through the evidence of Professor Henderson, there have been nineteen epidemiological studies on whether or not brake work increases the risk of mesothelioma, accompanied by two meta analyses and one qualitative review and none of them have ever disclosed any increase in risk." 78 For the reasons already given, his Honour was not in error in rejecting that objection. Arguably, that was the only objection which fell within the terms of the notice of appeal, as amended, which was identical in the case of each appellant. Nevertheless, the objection taken to the evidence that "all asbestos exposure was in an acceptable latency period causes or materially contributes to mesothelioma", which also appears to have been intended to be part of the appeal, has been addressed above. As both challenges to the admission of the evidence of the experts have been rejected, this ground of appeal must be rejected. 79 To the extent that the general objection remained unresolved until the final judgment, it was implicitly determined by rejecting the first submission of the appellants, noted at [18] above. It should have been the subject of an express ruling. However, because this aspect of the appeal is addressed under s 75A of the Supreme Court Act, because it is in any event clear why the trial judge admitted the evidence, and because the objection was properly rejected, nothing turns on this omission. (5) Grounds 1, 7, 8 and 10 – causation 80 As noted above, in a manner which is not entirely helpful in legal terms, the appellants divided their complaints in respect of causation into the separate categories of "general" and "specific" causation. Furthermore, the particulars of the respective grounds did not reflect any distinction between general principles and their application in the particular case, which might have been legally pertinent. Amaca expressed the relevant grounds as follows: " A General causation 1. The trial judge erred in point of law in deciding that the plaintiff established general causation – ie that asbestos inhaled during the course of the plaintiff's work could cause his injury. Particulars (a) The trial judge applied an incorrect legal test by finding that it was sufficient to establish general causation if science could not rule out a causal connection (see judgment at [40] and [82]); (b) The trial judge's decision was decided contrary to binding authority, to which he was taken in submissions and which [he] failed to apply or even refer: Seltsam v McGuiness ; (c) The trial judge reversed the onus of proof in respect of general causation (see judgment at [40], [55], [60], [63]-[66] and [82]); (d) The trial judge declined to address the whole of the evidence, or even to identify that evidence which he accepted or rejected (see judgment at [51]), and as a consequence failed to give adequate reasons; (e) the trial judge applied a decision made on its facts, EM Baldwin & Son Pty Ltd v Plane (see judgment at [58] and [60]) as though it created a rule of law. … C Specific causation 7. The trial judge erred in law in deciding that a breach of duty by Amaca caused the plaintiff's injury (see judgment [166] and [172]). Particulars (a) The trial judge erred in applying an incorrect legal test – viz that to prove causation in tort it is sufficient for a claimant to establish an increase in risk; (b) the trial judge erred in applying an incorrect legal test – viz that causation-in-fact may be inferred from a minimal increase in risk, that is whenever that increase in risk cannot be dismissed as de minimis (see judgment at [169] and [171]); (c) the trial judge erred in failing to apply the correct legal test – ie that merely increasing the risk of an injury occurring is insufficient to establish causation-in-fact unless the claimant proves that risk came home; (d) the trial judge carried out an erroneous analysis of the causal role of Amaca – viz by comparing Amaca's contribution with only the background risk, rather than the respondent's entire risk. 8. The trial judge erred in point of law by deciding causation while failing to refer, or to apply, the 'but for' test of causation. Particulars (a) The trial judge failed (at all) to refer to the 'but for' test of causation, and consequentially failed to apply the 'but for' test; (b) the trial judge failed (at all) to address specific submissions directed to the applicability and effect of the 'but for' test of causation on the facts of this case. … 10. The trial judge erred in point of law by finding (if he did) that causation was established by some understanding of a biological process. Particulars (a) The evidence was incapable of supporting causation through a biological process." 81 Amaba expressed the relevant grounds in the same terms, save that ground 8 was ground 9 and read 'by failing to refer' rather than 'while failing to refer'. 82 The distinction sought to be drawn between general and specific causation was better understood as a distinction between the following propositions: (a) Mr Booth's exposure to asbestos whilst in the employment of Amaca (or Amaba) did not materially contribute to his contraction of mesothelioma, and (b) If the relevant exposure did materially contribute to the injury, the material contribution did not make out causation by any breach of duty by Amaca (or Amaba). 83 Consideration of the second issue cannot be completed until the nature of the duty and the question of breach have been considered. The proposition that the trial judge reversed the onus of proof will be addressed below. (a) identification of legal test 84 In terms of legal principle, the strongest position taken by the appellants was the alleged failure of the trial judge to apply the correct legal test to the question of causation. However, at least at a high level of generality, the legal test was no more than whether or not the respondent established on the balance of probabilities that, in respect of each appellant, exposure to inhalation of asbestos liberated from its products materially contributed to his injury. 85 The secondary level of the appellants' position appeared to involve the following elements: (a) clinical observations of the respondent could not determine the cause of his mesothelioma; (b) in the absence of a scientific theory, tested and accepted according to scientific method, it was not possible to say that all of his exposure contributed materially to the injury, and (c) the only evidence of causation was the epidemiological evidence, which could not demonstrate causation on the balance of probabilities unless the relative risk attributable to the particular tortious exposure, as compared with all other exposures, approached two. 86 Propositions (a) and (c) may be accepted; proposition (b) may also be accepted, with some degree of qualification. The difficulty facing the appellants, however, was that the evidence called for by the respondent at trial was capable of supporting a finding of causation by satisfying (b) and, secondly, by satisfying (c). 87 Reference has been made above to part of the evidence of Professor Henderson, an internationally recognised expert in the pathology of asbestos-related diseases, particularly of the lung. In his report of 2 March 2009 Professor Henderson provided the following summary of factors relevant to causation (pp 21-23): Asbestos fibres including chrysotile are known Class 1 human carcinogens. The WHO has concluded that asbestos fibres including chrysotile have the capacity to induce both lung cancer and mesothelioma. No safe threshold level of asbestos exposure has been delineated for the carcinogenic risks from asbestos fibre inhalation, including chrysotile fibre inhalation. Although most inhaled chrysotile fibres probably do not reach the lungs, some are deposited therein, and chrysotile fibres can translocate to the pleura as shown by fibre analysis. In experimental models, chrysotile fibres introduced into the pleural cavity have the capacity to induce mesothelioma, with a potency similar to that of amphibole asbestos. The lesser potency of chrysotile asbestos for the causation of mesothelioma in humans is probably related to [four identified factors]; Commercial chrysotile asbestos from Quebec as used in brake blocks/linings/pads is known to have been contaminated with small amounts of fibrous tremolite (a non-commercial amphibole). Given the no-threshold model for cancer induction by asbestos, including chrysotile, exposures above background will, following an appropriate latency interval, confer an increment in risk on top of any underlying pre-existing background risk. … Exposures to asbestos dust from grinding of new brake blocks/linings/pads are known to have yielded increased airborne concentrations of respirable asbestos fibres. Such inhalation represents exposure in excess of any exposure derived from the general environment. It is not consistent to acknowledge the carcinogenicity of Canadian chrysotile for mesothelioma induction and then to argue that the same chrysotile in other circumstances (eg, exposure to Canadian chrysotile dust derived from brake blocks/linings/pads) has no carcinogenicity. Although some epidemiological studies have failed to identify an increased risk of lung cancer among brake mechanics, some have …. Data in Australian Mesothelioma Register – which records all mesotheliomas in a nation of almost 20,000,000 people – constitute the strongest evidence for an increased risk of mesothelioma among brake mechanics who ground and chamfered new brake pads/linings/blocks. 88 The opinion expressed by Professor Henderson in relation to cumulative effect of all exposure has been set out above at [50]-[51]. 89 This was not a case in which there was doubt as to the agent responsible for the injury. Nor was it a case in which a single exposure would necessarily cause the injury. Rather, as the primary judge held at [55], it was a case in which the evidence indicated that the incidence of mesothelioma increases in proportion to increased dose. Because, his Honour held, those who contract the disease probably have an underlying genetic susceptibility, the degree of exposure is relevant in such persons. His Honour concluded at [57]: "If the threshold dose were sufficient to explain the contraction of the disease in those persons, then increasing doses should yield few further cases of mesothelioma. The fact that the incidence rises with increasing dose suggests that the further exposure plays a causative part in the aetiology of the disease." (b) application of Seltsam: ground 1(b) 90 Findings as to the cumulative effect of exposure to asbestos were undoubtedly open. The respondent's witnesses, including Professor Henderson and Dr Leigh, sought to reconcile that approach with the epidemiology which suggested there was no increased risk in the case of brake mechanics. It was open to his Honour to accept their evidence, as he did. The underlying proposition put forward by the appellants, that the epidemiology was conclusive, in accordance with the principles applicable to such evidence, did not give rise to a question of law, but to a question of fact, which his Honour resolved against the appellants. The suggestion that the decision was contrary to binding authority, namely that of Seltsam Pty Ltd v McGuiness, must also be rejected. Seltsam Pty Ltd v McGuiness was a case in which the plaintiff relied solely on epidemiological evidence, which is not this case. (c) application of Plane: ground 1(e) 91 It is convenient in this context, to address the complaint that the primary judge applied the decision of this Court in EM Baldwin & Son Pty Ltd v Plane [1998] NSWCA 23; 17 NSWCCR 434, "as though it created a rule of law". 92 The reference to Plane occurs at [58] at which point his Honour quoted a passage from the judgment of Fitzgerald AJA at [94] in Plane, concluding that there was no error in the Tribunal in that case accepting Professor Henderson's view as to the "cumulative effect" of continued exposure. It is not possible to read the reference to that conclusion as either setting out, or applying, a rule of law. What the passages at [58]-[62] reveal is a degree of frustration that factual propositions, first established over 10 years ago, continue to be challenged by the present appellants and related parties, without calling their own medical evidence to challenge what Professor Henderson described as accepted medical opinion: see [60]. It will be necessary to refer later to the attempt to invoke s 25B(1) of the Tribunal Act, which is apparently intended to prevent repetitious challenges to matters of general application. (d) the "but for" test of causation: ground 8 93 It is convenient to address next what may be seen as a consequential argument, namely that if all exposure has a cumulative effect, a claimant cannot succeed unless he or she demonstrates that the particular exposure resulting from the tort of the defendant is one without which, the injury would not have occurred. The legal requirement to apply such a test was said to be "reaffirmed" in three recent decisions of the High Court, namely Adeels Palace Pty Ltd v Moubarak [2009] HCA 48; 239 CLR 420; Amaca Pty Ltd v Ellis [2010] HCA 5; 240 CLR 111 and Tabet v Gett [2010] HCA 12; 240 CLR 537. 94 Adeels involved a claim by Mr Moubarak, who was injured at a New Year's Eve function at a restaurant run by the appellant, Adeels. Following a fracas, a man who had been punched in the face by the plaintiff, left the restaurant, obtained a gun, returned and shot the plaintiff in the stomach. The High Court accepted that Adeels owed Mr Moubarak a duty "to take reasonable care to prevent injury to patrons from the violent, quarrelsome or disorderly conduct of other persons": at [26]. The next question was whether there was a breach of that duty in failing to have security personnel at the restaurant for the New Year's Eve celebrations. The Court did not answer that question because it was satisfied that, even had appropriate security personnel been present, the plaintiff did not establish that they would have prevented the harm suffered. In other words, he would have failed upon causation. The discussion as to principles governing causation is to be found at [41]-[57]. 95 It is undoubtedly correct to say that Adeels identifies principles of general relevance in relation to causation in tort. Nevertheless, the discussion was directed to the operation of s 5D of the Civil Liability Act 2002 (NSW). As the Court held that it was essential to direct attention first to the terms of that Act, to avoid a "serious risk that inquiries about duty, breach and causation will miscarry", it follows that regard must be had to the terms of the legislation in understanding the reasons given in that case: at [11]. That is particularly so in circumstances where the Court made reference to the statutory provision in order to distinguish such a case as the present. 96 The relevant provision in the Civil Liability Act, in respect of causation, is s 5D. Neither that provision, nor any other provision to be found in Pt 1A Negligence, applies to proceedings before the Tribunal: Civil Liability Act, s 3B(1)(b). Section 5D is to be found in Div 3 of Pt 1A, headed "Causation". The section relevantly provides: " 5D General principles (1) A determination that negligence caused particular harm comprises the following elements: (a) that the negligence was a necessary condition of the occurrence of the harm ( factual causation ), and (b) that it is appropriate for the scope of the negligent person's liability to extend to the harm so caused ( scope of liability ). (2) In determining in an exceptional case, in accordance with established principles, whether negligence that cannot be established as a necessary condition of the occurrence of harm should be accepted as establishing factual causation, the court is to consider (amongst other relevant things) whether or not and why responsibility for the harm should be imposed on the negligent party. … (4) For the purpose of determining the scope of liability, the court is to consider (amongst other relevant things) whether or not and why responsibility for the harm should be imposed on the negligent party." 97 The grammatical structure of sub-s (1) is curious: it should be understood as requiring that, subject to sub-s (2), a court should not find that negligence caused particular harm absent satisfaction that it was a "necessary condition" of the occurrence of the harm and that, subject to sub-s (4), the court is satisfied that it is "appropriate" for the negligent person's liability to extend to such harm. 98 The focus of the appellants' submissions was the element of a "necessary condition" in par (a). The qualification to that requirement was addressed in Adeels at [57] in the following terms: "It may be that s 5D(2) was enacted to deal with cases exemplified by the House of Lords decision in Fairchild v Glenhaven Funeral Services Ltd [2003] 1 AC 32 where plaintiffs suffering from mesothelioma had been exposed to asbestos in successive employments. Whether or how s 5D(2) would be engaged in such a case need not be decided now. The present cases are very different. No analogy can be drawn with cases like Fairchild ." 99 In relation to s 5D(1), the Court noted the division of the question of causation into two elements and continued: "43. Dividing the issue of causation in this way expresses the relevant questions in a way that may differ from what was said by Mason CJ, in March v E & M H Stramare Pty Ltd (1991) 171 CLR 506 at 515, to be the common law's approach to causation. The references in March v Stramare to causation being 'ultimately a matter of common sense' were evidently intended to disapprove the proposition 'that value judgment has, or should have, no part to play in resolving causation as an issue of fact'. By contrast, s 5D(1) treats factual causation and scope of liability as separate and distinct issues. 44. It is not necessary to examine whether or to what extent the approach to causation described in March v Stramare might lead to a conclusion about factual causation different from the conclusion that should be reached by applying s 5D(1). It is sufficient to observe that, in cases where the Civil Liability Act or equivalent statutes are engaged, it is the applicable statutory provision that must be applied." 100 The consideration then continued by reference to s 5D(1). The passage relied upon by the appellants came in the discussion with respect to the operation of s 5D(2), at [55]: "At once it must be recognised that the legal concept of causation differs from philosophical and scientific notions of causation. It must also be recognised that before the Civil Liability Act and equivalent provisions were enacted, it had been recognised that the 'but for' test was not always a sufficient test of causation. But as s 5D(1) shows, the 'but for' test is now to be (and has hitherto been seen to be) a necessary test of causation in all but the undefined group of exceptional cases contemplated by s 5D(2)." 101 Before turning to the general law principles with respect to necessary and sufficient causes, it is convenient to note the passages relied on in the two more recent decisions of the High Court. In Amaca Pty Ltd v Ellis, the claimant was the widow of a man who had died of lung cancer. He had smoked cigarettes over a period of some 26 years and had been exposed to respirable asbestos fibres in the course of employment with two employers. In the first, for a period of some three years, he had been exposed to asbestos when working with asbestos cement pipes manufactured by Amaca. 102 There are two aspects of Amaca v Ellis which should be noted before considering the passages in the judgment relied on by the appellants. First, the appeal from the trial judge to the Western Australian Court of Appeal was not limited to a question of law. Secondly, the facts were different in highly material respects, noted at the outset in their Honours reasons: "2. No scientific or medical examination can say why Mr Cotton developed lung cancer. His cancer was not, as some are, a cancer peculiarly associated with exposure to asbestos. … … 5. When, as here, medical and scientific examination cannot say whether exposure to respirable asbestos fibres was a cause of Mr Cotton's cancer, the medical practitioner and scientist have little choice but, as one witness said at trial, to 'take it into consideration in looking at what might have caused his lung cancer'. In their inquiries, the uncertainty about cause means that they cannot 'exclude it from the end result'." 103 As is evident from the foregoing discussion in these reasons, not only was the respondent's cancer one which was peculiarly attributable to inhalation of asbestos, but the evidence did ascribe a causal connection. 104 The primary complaint of Amaca in Amaca v Ellis, upheld by the High Court, was that the trial judge failed to direct attention to the causal connection between the negligence of each defendant and the lung cancer: at [38]. Their Honours stated: "Not only did this framing of the question not distinguish between defendants, it assumed … that cumulative exposure to asbestos, by the negligence of more than one defendant, would be sufficient to establish the relevant causal connection between a defendant's negligence and the damage suffered." 105 Their Honours noted that the plaintiff's argument was "first, that causation was established as a matter of inference not direct proof, and, secondly, that the inference of causation was to be drawn from a proper understanding of the epidemiological evidence": at [47]. Further, their Honours stated at [48]: "The plaintiff submitted that the majority's use of the word 'cumulatively' (in the expression 'tobacco smoke and asbestos fibres operated inter-dependently and thus cumulatively ') was 'unfortunate'. In particular, so the plaintiff submitted, it should not be understood as a reference to the kinds of process that lead to a condition like boilermakers' deafness or other forms of progressive disease or injury. Rather, the plaintiff submitted, 'cumulatively' should be understood as a reference to an interdependent (because synergistic or multiplicative) operation of the two carcinogens to which Mr Cotton was exposed – tobacco smoke and respirable asbestos fibres." 106 It is apparent from these passages that the issues being addressed in respect of causation were significantly different from those which have arisen in the present case. However, there is a passage in the judgment under the heading "The relevance of material contribution" which is presently important. "66. The plaintiff made a deal of reference to the decision of the House of Lords in Bonnington Castings Ltd v Wardlaw [[1956] AC 613] and, in particular, the statement of Lord Reid [at 621] that: 'What is a material contribution must be a question of degree. A contribution which comes within the exception de minimis non curat lex is not material, but I think that any contribution which does not fall within that exception must be material.' Particular attention was given to what was meant by saying that any contribution that was not de minimis must be material. 67. It is important to recognise the context in which this statement was made. The issue in Bonnington Castings was whether exposure to silica dust from poorly maintained equipment caused or contributed to the pursuer's pneumoconiosis, when other (and much larger) quantities of silica dust were produced by other activities at the pursuer's workplace. Those other activities were conducted without breach of duty. As Lord Reid rightly pointed out, the question in the case was not what was the most probable source of the pursuer's disease: dust from one source or the other. The question was whether dust from the poorly maintained equipment was a cause of his disease when the medical evidence was that pneumoconiosis is caused by a gradual accumulation of silica particles inhaled over a period of years. 68. This description of the issue of causation in Bonnington Castings shows how different it is from the issue of causation in this case. The issue in Bonnington Castings was whether one source of an injurious substance contributed to a gradual accumulation of dust that resulted in disease. The issue here is whether one substance that can cause injury did cause injury. Or, to adopt and adapt what Starke J said in Adelaide Stevedoring Co Ltd v Forst [[1940] HCA 45; (1940) 64 CLR 538 at 567], was Mr Cotton's cancer 'intimately connected with and contributed to' by his exposure to asbestos? Questions of material contribution arise only if a connection between Mr Cotton's inhaling asbestos and his developing cancer was established. Knowing that inhaling asbestos can cause cancer does not entail that in this case it probably did . For the reasons given earlier, that inference was not to be drawn in this case. Questions of what is a material contribution do not arise." 107 In the present case, the appellants complained that the trial judge misapplied the passage from Bonnington Castings quoted in Amaca v Ellis. The appellants submitted that Curtis DCJ must have misunderstood the reference to Amaca v Ellis because the issue in that case "is the same issue as here". However, that is not so. In the light of the evidence discussed above, relating to cumulative effect, the analogy with Bonnington Castings drawn by the primary judge was apt: at [170]. 108 The third of the recent High Court decisions relied upon by the appellants was Tabet v Gett. That case was primarily concerned with the question whether the loss of a chance of a better outcome was a sufficient form of damage, where an adverse physical outcome could not be demonstrated on the balance of probabilities to have been caused by the negligence of a medical practitioner. In relation to causation, Kiefel J (with whose reasons Hayne and Bell JJ and Crennan J separately agreed) stated in relation to causation at [111]: "111. The common law requires proof, by the person seeking compensation, that the negligent act or omission caused the loss or injury constituting the damage. All that is necessary is that, according to the course of common experience, the more probable inference appearing from the evidence is that a defendant's negligence caused the injury or harm. 'More probable' means no more than that, upon a balance of probabilities, such an inference might reasonably be considered to have some greater degree of likelihood; it does not require certainty. 112. The 'but for' test is regarded as having an important role in the resolution of the issue of causation, although more as a negative criterion than as a comprehensive test. The resolution of the question of causation has been said to involve the common sense idea of one matter being the cause of another. But it is also necessary to understand the purpose for making an inquiry about causation and that may require value judgments and policy choices." 109 Tabet was not a case governed by the Civil Liability Act, but by general law principles. Those general law principles undoubtedly include the concept of "material contribution". That concept does not apply in all cases, but it does in cases where a causal connection involves a number of elements. It applies in cases involving "multiple sufficient causes", a phrase used in Trindade, Cane and Lunney, The Law of Torts in Australia (4th ed, 2007) at p 554. 110 Where separate tortfeasors have contributed to an indivisible injury, there may be an apportionment of responsibility between them. Where there is a non-tortious contribution (whether due to a genetic disposition, a pre-existing injury or some other non-tortious cause) allowance may need to be made in the assessment of damages for the possibility that the injury would have happened absent the tortious exposure: see Malec v JC Hutton Pty Ltd [1990] HCA 20; 169 CLR 638. 111 These authorities do not support the proposition that the primary judge misapplied the general law test of causation: ground 8 must be rejected. 112 The appellants placed considerable weight, in relation to "but for" causation, on some evidence of Dr Leigh; indeed, at times it appeared that their sole complaint in relation to "but for" causation was that the evidence had not been acted upon. 113 The evidence was (Tcpt 26/2/10, p 270) – "Q. … Dr Leigh, you can't say that except for the brake work Mr Booth wouldn't have got his mesothelioma, can you? A. No, I can't say that. Q. What you're saying is you can't exclude the brake work. A. Yes." 114 The appellants submitted that, from this evidence alone, "but for" causation could not be found. That is not correct. Contraction of mesothelioma independently of exposure from work as a motor mechanic could not be excluded, but that is not a denial of "but for" causation. (e) finding based on biology or assessment of risk: grounds 7 and 10 115 It is difficult to encapsulate the appellants' propositions in respect of these issues in a simple statement. The appellants' position appears to divide the possible causal link into two categories, namely demonstration of a biological process or demonstration of increased risk. They accept that the latter can give rise to a finding of causal connection, but only if the relative risk is calculated at a figure approaching two, when the comparison of the tortious risk as a proportion of all other risks will constitute approximately 50%. The evidence, the appellants contended, did not approach that figure. Accordingly, to the extent that his Honour relied upon an increase in risk, as the basis of his finding of causation, he was in error; to the extent that his Honour relied upon a biological explanation, there was none which could give rise to satisfaction on the balance of probabilities as to the relevant causal link. 116 It is convenient to deal first with the challenge to the "biological process" evidence. The appellants submitted that such evidence was "incapable" of supporting a finding in favour of the respondent, for three reasons. First, it was said that the biological processes remain "incompletely understood". That assessment of scientific understanding may be accepted; but it takes the appellants nowhere. The civil standard of proof, on the balance of probabilities, permits a yawning gap between complete understanding and sufficient understanding. There may be an even greater gap between that which is "capable" of supporting a finding on the balance of probabilities and that which the appellants would accept "does" support such a finding. The submission misconceives the nature of the proceedings. 117 The second reason given was that the experts "preferred" to define the state of medical science in terms of an increased "risk" of contracting mesothelioma. The experts "appeared", it was submitted, to use the word "caused" as a synonym for an increase in risk. 118 This submission is also based on a misconception. It is a submission for the trial judge not for this Court. As has been adequately demonstrated above, there was evidence (from Professor Henderson among others) which provided a more than adequate basis for a conclusion that all inhalation of asbestos contributed to the injury. Furthermore, the references to the oral evidence of Professor Henderson, relied upon by the appellants, did not support the conclusion for which they were cited. For example, at Tcpt, 23/02/10, p 117 Professor Henderson was asked: "Q. In the case of Mr Booth, are you able to say whether or not that particular risk of that last exposure came home? A. No. I'd say particularly the risk from all of his exposures came home because the model which I adopt is that of a cumulative exposure dose response, so I think that all of the asbestos fibres that he's inhaled, or at least a proportion of them, will contribute to the risk and to the ultimate development of the mesothelioma." 119 That evidence, which his Honour effectively accepted, distinguished between the risk and the event. Thus, a person who is in a room containing asbestos dust is at risk of inhaling asbestos fibres. If the risk materialises and the fibre is inhaled, he will be at risk of some fibres lodging in his lung. If that happens, there is a risk that some of those fibres will translocate to the pleura. If that happens, he is at risk of contracting mesothelioma. The concept of "risk" looks at the matter prospectively; if the risk materialises, a causal connection may be inferred. Professor Henderson's evidence accepted the causal connection at each stage. It was open to his Honour to conclude that Professor Henderson, for example, did not use risk synonymously with cause and to conclude that Professor Henderson did not "prefer" to describe the state of medical science in terms of risk; indeed, he described "risk" as "a very bad term": Tcpt, p 117. 120 The second submission is not made out factually, nor if it were, would it demonstrate that the evidence set out above was not capable of supporting the finding of causation. 121 The appellants' third submission was that the biological process postulated was "undermined" by evidence that "not all of the asbestos was necessary to produce the outcome". A passage relied on in Professor Henderson's evidence for that proposition was his acceptance of the statement that each exposure was an increment to the risk: Tcpt, p 117K. However, that is to say no more than that there were multiple contributing causes, a proposition addressed above. The further statement that "[t]his kind of evidence" was rejected as insufficient to demonstrate biological causation in Amaca v Ellis ignores the differences in the issue and the evidence in that case. 122 The alternative approach concerned the use by the trial judge of the epidemiology. The appellants complain that his Honour conflated the concepts of increase in risk and causation. In one passage in the written submissions, it was asserted that the trial judge "framed his critical finding on causation in the terms of an increase in risk": Amaca submissions, par 68. The reference (and the quotation) was to the primary judgment at [184], which read: "Although, as the epidemiological evidence reveals, the risk faced by Mr Booth was not high, it was certainly a risk recognised before 1953, and it is a risk which has come home." 123 It was erroneous to describe this passage as the "critical finding on causation". His Honour had ceased to deal with causation twelve paragraphs earlier: in the passage quoted, he was addressing foreseeability in relation to the case against Amaca, as is clear from the reference to the date, 1953, which was the beginning of Mr Booth's employment as a motor mechanic. 124 The appellants also complained about the manner in which his Honour dealt with epidemiological evidence with respect to risk. The complaint was that his Honour translated risk into cause "as though they were the same thing": Amaca's submissions, par 67. In the notice of appeal, the error of law was said to arise from the finding that any minimal increase in risk (that is, one which is not de minimis) is sufficient to demonstrate a causal connection. 125 The underlying error in this submission is that it takes a part of the judgment which was not critical to the conclusion and treats it as a necessary part of the reasoning. To explain how that has happened, it is necessary to refer back to the structure of the judgment. 126 The trial judge summarised the plaintiff's case in relation to causation at [22]-[38]. In so doing, he set out passages from the evidence, including those from Professor Henderson's evidence set out above. He also identified the key issue in the plaintiff's case at [22], set out at [16] above. After addressing specific arguments raised by the appellants, his Honour concluded at [59]: "At issue between the parties in this case is the proposition that all exposure to chrysotile asbestos, other than trivial or de minimis exposure, that occurred in a latency period of between 26 and 56 years, materially contributed to the cause of Mr Booth's mesothelioma. I resolve that issue in favour of the plaintiff." 127 It is necessary to return to his Honour's statement of the appellants' case as set out, in four propositions, at [39] set out at [18] above. 128 Submission (1) had two parts: the first, that medical science cannot support causation, formed the basis of the admissibility argument. That has been dealt with above. However, it also formed a substantive objection, which lay at the heart of the appellants' defence. Under the heading "The Limitations of Medical Science" his Honour rejected that submission, based on his assessment of the medical science: at [40]-[62]. 129 Submission (2), as to the unlikelihood of the respondent's work causing mesothelioma, which might have been seen as supportive of the first submission, was addressed by his Honour under the heading "Improbability of the Causal Mechanism" at [63]-[66]. 130 Submission (3), based on the epidemiological studies, might also have been thought to support the first submission and was dealt with by his Honour under the heading "Epidemiological Evidence" at [67]-[82]. (It will be necessary to return to aspects of that reasoning, in particular at [81].) 131 Submission (4) was that the exposure to asbestos derived from products of either Amaca or Amaba was "insignificant" in comparison with other exposures. This submission was addressed by his Honour under the heading "Quantification of Exposure" at [83]-[94], "The Estimates of Cumulative Exposure" at [95]-[96], "Mr Pickford's evidence" at [97]-[101], "Exposure loading trucks" at [102]-[115], "Exposure in Home Renovations" at [116]-[139], and "Mr Rogers' Evidence", including loading trucks, renovations and brake work, at [140]-[153], and in "Additional reservations concerning the evidence of Mr Pickford and Mr Rogers" at [154]-[160]. 132 Out of this lengthy discussion, the appellants extract (and apparently accept, subject to one qualification), the contribution of brake repair work to the "combined lifetime risk" in respect of mesothelioma. His Honour identified the increase in fibre burden created by the brake work at approximately 44% above the background risk: at [137]. The qualification to the appellants' acceptance of the calculation was the complaint that his Honour's analysis was "erroneous" because it only compared Amaca or Amaba's contribution with the background risk and not with the entire risk not attributable to each defendant. What in fact his Honour did was to divide the exposure due to brake work proportionately according to the periods of exposure to Amaca products and Amaba products: at [163]-[168]. If this exercise involved some arithmetical error, it was an error of fact, not law. 133 More importantly, in making the calculations his Honour stated that he did not think "that the mathematics are necessarily compelling", continuing "if it were necessary to assign mathematical weight to the exercise", then he would assign 10% of the additional fibre burden to Amaca and 20% to Amaba. The qualified way in which the finding was made demonstrates that his Honour did not rely upon these figures as part of his essential reasoning. In his conclusions on causation, he stated that the evidence of fibre burden, did "prove to my satisfaction that the plaintiff's exposure to the asbestos contained within brake linings materially contributed to the causes of his mesothelioma": at [161]. However, his Honour continued at [162]: "In any event, proof of causation in this case does not turn upon the epidemiological evidence, or upon questionable estimations of total fibre burden. An overwhelming inference of causation may be drawn from the following facts: (1) Mr Booth's mesothelioma was caused by the inhalation of asbestos fibre; (2) Mesothelioma very rarely occurs in persons who have not been exposed to asbestos fibres beyond the background level that pervades urban environments; (3) For a total of 27 years, week in and week out, Mr Booth was additionally exposed to asbestos fibres liberated from asbestos brake shoes by his own work, and by the work of others in his vicinity, (4) The previous exposure, in the course of home renovations and truck loading was, in comparison, trivial." 134 It was these findings which had to be shown, both to be erroneous and in respect of a point of law. 135 The challenge raised by grounds 7 and 10 did not go to these findings: the ground must therefore be rejected. (f) reversal of onus of proof: grounds 1(a) and (c) 136 The appellants claimed that his Honour applied an incorrect legal test by finding that it was sufficient to establish general causation if science could not rule out a causal connection. These grounds are based on a misreading of the judgment. 137 Ground 1(a) relied upon two paragraphs in the judgment which were in the following terms: "40. I reject the submission that medical science cannot support the proposition that all asbestos inhaled materially contributes to the causes of mesothelioma. … 82. I am not persuaded that the epidemiological evidence specific to automotive mechanics is adverse to the submission that causation has been proved in this particular case." 138 The structure of his Honour's judgment has been outlined above. Paragraph [40] was not a conclusion on an ultimate issue: it was the rejection of submission (1) put by the appellants, as identified at [39]. (The fact that it preceded the reasoning which supported it is neither here nor there.) The second passage, at [82] served an identical purpose: it was the conclusion of a lengthy discussion rejecting submission (3). Ground 1(a) is untenable. 139 Ground 1(c) asserted a reversal of the onus of proof in respect of those two paragraphs and three sets of additional paragraphs. The first, [55] was in the following terms: "Uninstructed by medical evidence, I would not regard Mr Watson's suggestion that mesothelioma may be contracted by exposure to a threshold dose, with further exposure irrelevant, as consistent with the epidemiological evidence that the incidence of mesothelioma increases in proportion to increased dose." 140 As with the paragraphs referred to earlier, this is in express terms a rejection of a submission put by the appellants: on no reading could it constitute a reversal of the onus of proof. 141 The next passage, at [60] has been outlined at [92] above: a comment that evidence of the cumulative effect of all exposures had been given in Plane 10 years ago, but the appellants had called no evidence to counter it likewise does not involve any reversal of the onus of proof. It is merely a statement that the evidence supporting the plaintiff's case was unanswered. 142 The final passage relied upon, at [63]-[66], is of the same kind, namely a rejection of appellants' submission (2). Grounds 1(a) and (c) must be rejected as entirely misconceived and without merit. (g) failure to give adequate reasons: ground 1(d) 143 Enough has been indicated already to demonstrate that, with the possible exception of the ruling of no evidence, his Honour set out his reasons in some detail. The ground of inadequate reasons is, understandably, not directed to the ultimate findings, but is limited to a statement at [51]. That paragraph commenced with the statement, "[b]ecause the defendants call no medical evidence, it is unnecessary to review in further detail the evidence from the plaintiff's medical witnesses". That statement was made in the course of rejecting submissions as to the limitation of medical science. In fact the very same paragraph continued: "I think it sufficient to observe that the mechanical theory and the chemical theory of causation are not competing but complementary, and that the complete carcinogen theory is not incompatible with the proposition that all exposure materially contributes to the development of the mesothelioma." 144 In oral submissions, senior counsel ranged more broadly in his complaints about the inadequacy of the reasons. As is commonly the case, the complaint was really one of disagreement with the reasons, which does not demonstrate inadequacy. A possible exception was the complaint concerning [81] of the trial judge's reasons. 145 Paragraph 81 was part of the trial judge's consideration of the epidemiological evidence. The consideration included reference at [76] to Dr Leigh's criticism of the studies on which the appellants relied "upon the basis of weak case reference design, and low statistical power", and his Honour's rejection at [80] of the proposition that the epidemiological data showed that employment as a motor mechanic did not increase the risk of developing mesothelioma. The trial judge said at [81]: "Dr Leigh argues that much of the data does support a strong correction between exposure to asbestos as an auto mechanic and the contraction of mesothelioma. I do not propose to canvass his evidence on this matter, nor do I think it necessary to repeat the persuasive detail contained in the thorough written submissions prepared by counsel for Mr Booth." 146 The appellants complained that the trial judge not only failed, but expressly declined, to expose his reasons. They referred to Wiki v Atlantis Locations (NSW) Pty Ltd [2004] NSWCA 174; (2004) 60 NSWLR 127 and Commissioner for Railways (Queensland) v Peters (1991) 24 NSWLR 407, although the latter was an entirely different case. 147 The trial judge was giving reasons in a case in which there was no appeal on fact. He made sufficiently clear in the paragraph what he accepted and, by the reference to the written submissions, why he accepted it. There was no failure to give adequate reasons. Ground 1(d) must be rejected. (6) Findings under s 25B (a) appeal: ground 11 148 The trial judge noted that the President of the Tribunal had determined in an earlier case involving Amaca that, for the purpose of s 25B of the Tribunal Act, "all asbestos exposure within an acceptable latency period, makes a material contribution to the [mesothelioma]": (Re Jones-Mashman) Amaca Pty Ltd v CSR Ltd (No 2) [2009] NSWDDT 24 at [7]. The statement in Amaca v CSR was somewhat qualified, O'Meally P having said, "[i]f it be necessary to do so … I determine as an issue to which s 25B applies …". 149 Section 25B so far as relevant, reads as follows: " 25B General issues already determined (1) Issues of a general nature determined in proceedings before the Tribunal (including proceedings on an appeal from the Tribunal) may not be relitigated or reargued in other proceedings before the Tribunal without the leave of the Tribunal, whether or not the proceedings are between the same parties. (1A) If an issue of a general nature already determined in proceedings before the Tribunal (the earlier proceedings ) is the subject of other proceedings before the Tribunal (the later proceedings ) and that issue is determined in the later proceedings on the basis of the determination of the issue in the earlier proceedings, the judgment of the Tribunal in the later proceedings must identify the issue and must identify that it is an issue of a general nature determined as referred to in this section." 150 Despite the earlier ruling by the President, s 25B does not appear to have been relied upon in the present case, so as to preclude relitigation of the issue of a general nature identified by the President in the earlier decision. In order to invoke the operation of the section, it is necessary to give notice of that intention: Dust Diseases Tribunal Rules, r 9(1). However, r 9(2) states that sub-r (1) "does not prevent the Tribunal from determining on its own motion that an issue is an issue to which s 25B(1) of the Act applies". 151 It may have been r 9(2) which caused his Honour to state at [62]: "Upon the facts in this case I specifically determine for the purpose of s 25B that all exposures to chrysotile asbestos, other than trivial or de minimis exposure, occurring in a latency period of between 25 and 56 years, materially contributes to the cause of mesothelioma." 152 It is this last statement to which the appellants take objection. The appellants submitted that there was no power to make such a determination and no utility in doing so. If so, there is raised a question as to the right to appeal against such a determination and the utility of the appeal. In the matter of R v Jamieson, Elliott and Blessington (1992) 60 A Crim R 68, an issue arose as to whether the Court of Criminal Appeal could set aside a statement by the trial judge in his sentencing judgment recommending that the prisoners should never be released. The remark was intended to influence the system whereby offenders sentenced to life imprisonment could obtain release on licence as an exercise of executive clemency. In the Court of Criminal Appeal, Gleeson CJ stated (p 80): "There does not appear to have been any statutory basis for the making of the 'recommendation', nor, for that matter does there seem to be any statutory basis for appealing against it." 153 The statement was later given legislative effect and an attempt was made in 2006 to reopen the appeal to the Court of Criminal Appeal. That attempt was unsuccessful: R v Elliott; R v Blessington [2006] NSWCCA 305; 68 NSWLR 1; 164 A Crim R 208. An appeal to the High Court was dismissed: Elliott v The Queen; Blessington v The Queen [2007] HCA 51; 234 CLR 38. 154 The determination made by his Honour at [62] did not purport to have any consequence for the present proceedings. Its effect, if it had any, would arise in subsequent proceedings. Procedurally, his Honour may have thought it of assistance to parties in future litigation to identify the issue of a general nature in terms which would allow the rule and the section to be invoked with a degree of certainty. 155 It is not necessary to consider whether that purpose is likely to be realised: it is sufficient to note that the determination does not, of itself, constitute a decision having legal force and effect. It certainly did not find its way into the orders in this case from which an appeal may be brought. 156 An appeal would only be available in respect of the determination in [62] if it involved a decision of the Tribunal in point of law. That could only arise if the primary judge were purporting to make a decision affecting the rights of parties, either in the present proceedings or in relation to future proceedings which might involve the appellant. There is, however, no indication that his Honour was purporting to make a determination which was binding on the Tribunal or parties in future proceedings. If a plaintiff in future proceedings sought to rely upon an issue of a general nature determined in these proceedings, it would be a matter for the Tribunal in the later proceedings to determine whether such an issue had been determined, and if so, how the issue should be identified. That point could arise without a determination of the kind found in [62]. The indication by the Tribunal in the present case that it considers a particular general issue to have arisen and been determined might be of assistance in allowing for the future operation of s 25B without unfairness to one party or the other. However, there is no necessary implication that his Honour was purporting to decide the matter in a way which would bind in the future and hence make a decision of a kind which might be subject to appeal under s 32 of the Tribunal Act. (b) judicial review: ground 5 of summons filed 3 June 2010 157 In the application under s 69 of the Supreme Court Act, each of the appellants claimed an order "quashing the orders of Judge Curtis made on 10 May 2010". No relief was claimed specifically in relation to the "determination" to be found in [62]. Had such an order been sought, it would have been necessary for the appellants to engage with the issues identified in Aronson, Dyer and Groves, Judicial Review of Administrative Action (4th ed, 2009) at pp 820-825. This was not done. 158 Accordingly, neither ground 11 (in the respective notices of appeal), nor ground 5 (in the respective summonses) provides a basis for relief. (7) Duty of care: foreseeability – Amaca: ground 12 159 Because the products with which the respondent worked were manufactured by the appellants in different periods of time, the question of foreseeability arose at different points in respect of each and was separately dealt with by his Honour in respect of each appellant. The ground of appeal in respect of Amaca was in the following terms: "12 The trial judge erred in point of law in deciding that in 1953, or at any time from 1953 to 1962, it was reasonably foreseeable that a automotive mechanic could suffer an injury of the kind suffered by the plaintiff (see Judgment at [186]). Particulars (a) The trial judge made a finding of foreseeability where there was no evidence (and no reference to any evidence) which could support the factual finding (see judgment at [181]); (b) The trial judge applied an incorrect legal test to determine reasonable foreseeability – viz by applying a generalised test, insufficiently specific to this case, or the facts of this case (see judgment at [181]); (c) The trial judge failed to determine foreseeability with reference to the class of persons into which the plaintiff fell; (d) The trial judge applied an incorrect legal test to determine foreseeability, by using the reference point of any asbestos-related disease rather than by reference to the facts of the case (see judgment at [186]); (e) The trial judge declined to identify the evidence upon which he relied (and 'other documents in evidence to which I have not referred' ) which lead to the finding of foreseeability, as a consequence of which he failed to give adequate reasons (see judgment at [181])." 160 These complaints give rise to two issues of principle, namely: (a) the level of generality at which a finding of a duty of care is to be made, and (b) the extent to which a finding that a duty of care exists is immune from review. 161 As explained by Windeyer J in Mount Isa Mines Ltd v Pusey [1970] HCA 60; 125 CLR 383 at 397-398: "Foreseeability here predicates the foresight of a reasonable man. … He is a man who notionally stood in the shoes of the defendant and had such knowledge, and capacity for care and foresight, as that defendant actually had and in addition such as a reasonable man in that position is expected to have. He is, in the words of Lord Wright in Bourhill v Young [1943] AC, at 111, 'a reasonable hypothetical observer'. He is not a seer who can foretell future occurrences that are quite unlikely according to the natural and ordinary course of events. Happenings that were fortuitous, in the sense that no reasonable man would have thought of them as within the range of possible consequences, cannot be said to have been reasonably foreseeable. And knowledge after the event, when it is easy to be wise, cannot shew that the event was foreseeable." 162 His Honour later stated, at 398-399: "Whether at some time in the past the prospect of the happening of an event which in fact happened was such that it created an obligation to take precautions against it is called a question of fact. It is really a value judgment upon ascertained facts." 163 The value judgment may be described as a decision in point of law, but based upon ascertained facts. In the present case, the relevant facts must be those which were either known, or ought reasonably to have been known, to a manufacturer of asbestos products in, first, 1953. 164 His Honour noted at [175] that "[i]n 1939 the UK Inspector of Factories reported that, "it is not many years ago when the dust of asbestos was regarded as innocuous, while today it is recognised as highly dangerous". His Honour continued at [176]: "Dr Smith, Director-General of Health in New South Wales, in his 1948 report confirmed the concern of industrial physicians and hygienists in relation to exposures to even small amounts of asbestos. At page 70 Dr Smith wrote in relation to a metal casting process: 'The exposure to asbestos was intermittent and of short duration, about five minutes at each pouring, and, as at the time asbestos was being used two or three times a week the dust hazard was considered to be small. However, in view of the dangers associated with asbestos dust it was advised a substitute such as magnesia… should be used.'" 165 His Honour referred to a number of articles and reports, available prior to 1953, which indicated an understanding of the dangers of working with asbestos in manufacturing. This was evidence from which it was open to be inferred that Amaca, as one of the major manufacturers of asbestos products in this country, would then have been aware of the fact that inhalation of asbestos dust was considered "highly dangerous". Inferences of this kind were drawn by the trial judge and involved findings of fact which could not properly be challenged on this appeal or by way of judicial review. In respect of brake linings which contained asbestos, which might be liberated as dust in a number of ways, the question was whether a duty of care was imposed on the manufacturer to take reasonable steps to avoid injury to workers using such products. That involved a question of law, based on findings of fact. 166 A factual finding was also to be made concerning the mechanism by which asbestos dust was created. His Honour found: "19. Asbestos fibre was liberated from new brake linings in three ways. First, by Mr Booth using a hammer to punch a rivet through the brake lining so as to fix it to the metal shoe. The holes provided in the brake lining for the rivets did not line up exactly with the holes in the shoe. Secondly, by Mr Booth using an electric drill to ream out the holes for the rivets, when the misalignment was too great to allow the rivet to be forced through with a punch. Thirdly, by grinding the leading edge of the brake lining on a bench grinder to ensure smooth operation of the brakes; this was a very dusty process. 20. The liberated asbestos collected upon Mr Booth's clothes, the work-bench, and floor of the workshop. It was re-agitated into the atmosphere by brooms, passing feet, and the use of compressed air to clean the workbench. 21. Mr Booth said that it took four hours to replace the linings on a passenger vehicle, and up to three hours per wheel to replace the linings on commercial trucks." 167 There was no evidence called by Amaca (or for that matter Amaba) to suggest that the companies did not know how brake linings were inserted and removed or that dust was liberated in those processes. Rather, the first passage of which the appellant Amaca complains is that at [181], following a review of published articles dating from 1930-1957: "This material and other documents in evidence to which I have not referred, persuade me that by 1953 — when the plaintiff began working as a motor mechanic — the inhalation of asbestos fibre by motor mechanics working on brake linings was generally recognised as dangerous, even at exposure levels below industrial standards, because of individual susceptibility to the cumulative effect of fibre inhalation, and the fact that no safe lower limit had been established." 168 Ground 12(a) referred to this paragraph as involving "the factual finding" of foreseeability for which there was no supportive evidence. In fact, as became apparent in the course of submissions, the paragraph does not make a finding as to foreseeability, but identifies that which was "generally recognised as dangerous" being a composite fact with a number of elements. The second complaint made about this paragraph was that it applied a "generalised test" insufficiently specific to this case: ground 12(b). There may be a real issue as to the level of generality at which a finding of foreseeability should be made, lest it be either meaningless (at too high a level) or too specific, thus eliding the separate concepts of duty, content of duty and breach. However, these factual findings cannot be said to be at too high a level of generality. 169 The third complaint was that foreseeability was determined without reference to the "class of persons" into which the plaintiff fell. The complaint was without foundation: his Honour expressly referred to "motor mechanics working on brake linings", which satisfies the relevant test. 170 Finally in relation to this paragraph, the appellants relied on the reference to "other documents in evidence to which I have not referred" as demonstrating an inadequacy of reasons. However, if the material to which reference was made was sufficient to allow the relevant inferences to be drawn, the fact that there was other material in evidence, supportive of those inferences, cannot assist on an appeal limited to a decision of the Tribunal in point of law. Nor can it demonstrate error on the face of the record for the purposes of prerogative relief. Judgments are not inadequate simply because the trial judge notes that there was further material of a supportive kind. 171 The appellants' complaints as to inferences drawn from the documents will be addressed below. The substance of the legal complaint was expressed in the following passage in par 90 of Amaca's written submissions: "… upon the trial judge's test if there was any knowledge of any risk of any diseases to any class of industrial user in respect of any level of exposure and in respect of inhaling any type of asbestos, then that was sufficient to establish reasonable foreseeability in relation to a particular disease (here, mesothelioma), in relation to a particular class (here, motor mechanics), in respect of a particular level of exposure (here, light and intermittent) and in respect of a particular type of asbestos (here, chrysotile)." 172 Unfortunately, there is a degree of hyperbole inherent in this submission. It was not correct to assert that his Honour referred to "any class of industrial user" (he referred to "motor mechanics working on brake linings"), nor was it correct to say that he referred to "any level of exposure", when he referred to a class of persons "regularly and cumulatively exposed to the inhalation of asbestos fibres released from asbestos products upon which they worked in an industrial setting": at [183]. The words "light and intermittent" were Amaca's characterisation, not that adopted by the trial judge. Finally, although it is true that his Honour did not specify a particular type of asbestos, he relied upon material which did not distinguish between, for example, chrysotile and crocidolite. 173 Ground 12(d) in the notice of appeal (though not the summons, which contained no particulars) took issue with his Honour's conclusion at [186]: "I find that in 1953 it was reasonably foreseeable by Amaca that an automotive mechanic who was, in the course of every week over many years, exposed to the inhalation of asbestos fibre released from brake linings upon which he worked with grinding tools, may contract an asbestos related disease." 174 The complaint in relation to this passage is that the finding of foreseeability was not specific to mesothelioma. 175 It was also incorrect to say that his Honour looked to the risk of "any diseases": he was concerned with asbestos-related diseases (meaning diseases caused by inhalation of asbestos) but not specifically mesothelioma. What Amaca needed to demonstrate was that a legally correct statement of the duty of care had to identify the specific disease which eventuated, rather than a range of possible diseases. 176 To make good its legal propositions, Amaca relied upon three cases. It is convenient to address first the decision of the High Court in Sydney Water Corporation v Turano [2009] HCA 42; 239 CLR 51. 177 Questions of foreseeability may arise in relation to the existence of a duty of care, in relation to whether particular conduct constitutes breach of the duty and in relation to the extent of damages recoverable. At the first point, it is commonly said that factual findings may be made at a higher level of generality when dealing with duty, than when dealing with breach: see Vairy v Wyong Shire Council [2005] HCA 62; 223 CLR 422 at [73] (Gummow J) approved by the Full Court in Turano. However, as his Honour also said in Vairy, the level of abstraction should not be such as to render the formulation of duty in terms which are "devoid of meaningful content". McHugh J in Vairy noted at [26] that: "… the duty owed by motorists to other users of the highway, for example, is expressed in terms of the duty to take reasonable care for the safety of other users of the highway having regard to all the circumstances of the case. The duty is not subdivided into categories such as a duty to keep a proper lookout or sound a warning or to keep a safe distance away from the car in front. In the particular circumstances of the case, failure to do one or more of these things may constitute a breach of the duty to take reasonable care. But they are not themselves legal duties for the purpose of the law of negligence. If they were, a trial judge would be bound to direct a jury in the circumstances of a particular case that the defendant had a duty to keep a proper lookout or sound his or her horn, as the case may be." 178 To similar effect, Hayne J stated that "a statutory authority, having the care, control and management of land to which the public has access, owes a duty of care to those who enter": at [117]. His Honour continued at [118]: "That may suggest that an attempt should be made to define the content of the Council's duty of care more precisely. Subject to one qualification, that would not be a useful exercise. The qualification is that it is necessary to recognise that the duty of care, owed by a statutory authority to those who enter land of which the authority has the care, control and management, is not a duty to ensure that no harm befalls the entrant. It is a duty to take reasonable care. Beyond that, however, it is not possible to amplify the content of the duty without reference to particular facts and circumstances. In each case, the content of the duty will turn critically upon the particular facts and circumstances." 179 Hayne J further noted that because the inquiry in this respect is prospective, "it would be wrong to focus exclusively upon the particular way in which the accident that has happened came about": at [124]. 180 In the present case, the question was whether Amaca, as the manufacturer of products containing asbestos, owed a duty to take reasonable care in the manufacture and distribution of such products to workers who might be required to grind or otherwise manipulate the product in such a way as to release asbestos. No doubt the particular nature of particular products and their intended purpose may require those characteristics to be taken into account in a particular case, but once it is known that release of asbestos dust causes a risk to health, the duty does not need to be defined more precisely. The fact that the ingestion or inhaling of asbestos may affect different individuals in different ways will not affect the existence of the duty. Accordingly, his Honour was entitled to consider the facts by reference to asbestos-related disease, rather than the specific disease suffered by the respondent. Grounds 12(b)-(d) should be rejected. 181 There remains a question as to whether the appellants are correct in saying there was "no evidence" (and no reference to any evidence) which could support the factual findings. The first document referred to by the primary judge was by Merewether and Price, United Kingdom, Home Office, Report on the Effects of Asbestos Dust on the Lungs and Dust Suppression in the Asbestos Industries (1930). The report concluded that "the inhalation of asbestos dust over a period of years results in the development of a serious type of fibrosis of the lungs", p 4, which was then described: p 9. The report acknowledged that different asbestos processes cause different amounts of dust in the air of workrooms and that in some processes the level of dust was insignificant: p 12. The report noted that the concentration of dust and the length of exposure were relevant factors, although the evidence as to how those factors operated was then far from clear: p 13. There was considerable discussion as to the processes giving rise to dust and methods for its suppression, in Part 2 of the report. Of seven industries considered, the fourth was "brake and clutch linings": p 18. In the introduction to a consideration of these industries, the report noted at p 19: "Apart from manufacture, certain work is carried on in premises subject to the Factory and Workshops Acts, as well as in other premises, which involves use or manipulation of asbestos or products containing it." 182 The discussion of brake and clutch linings was given separate consideration, although the description of the process (at pp 28-29) focused primarily on manufacture. The same is true of the summary and recommendations of the report. Nevertheless, the passages noted above indicate that the essential concern was exposure to asbestos dust, the mechanism being relevant only as a cause of such exposure. 183 The second article referred to, "Silicosis and Asbestosis: Memorandum on Industrial Diseases of Silicosis and Asbestosis" (October 1932), was published in a journal known as The Quarry and Road Making, at p 420. The appellants described the article as of unknown provenance and in "an obscure publication". The appellants asserted that although the respondent instructed two experts to carry out a literature research, neither referred to the article. 184 As the respondent pointed out, that statement was erroneous. In a report of 20 July 2009, Dr James Leigh, identified some 30 specific papers published before 1940 referring to the dangers of asbestos, including that article. (The appellants' written submission in reply did not acknowledge the error; it was acknowledged in oral submissions.) The article noted that various processes involved exposure to asbestos dust, including "the sawing, grinding and turning in the dry state of articles composed wholly or partly of asbestos such as motor car brake and clutch linings …": p 422. 185 The appellants also asserted a factual matter, namely that there was no evidence that the article "ever came to Australia". The respondent identified an exhibit demonstrating the contrary: Ex PX29, Annexure 11. Dr Leigh said that "[q]uantified dust levels in asbestos work were first reported in New South Wales in 1938' and various attempts were made to establish a threshold level of exposure: Ex PX22, p 4. 186 The third article relied on by the primary judge was the United Kingdom Home Office's Annual Report of the Chief Inspector of Factories for the Year 1938 (July 1939), which noted the recognition of asbestos dust as "highly dangerous": at p 63. 187 The fourth document was the New South Wales Department of Public Health's Report of the Director-General of Public Health NSW, 1948. The appellants stated that there were "only minor references to asbestos". That was true, but largely beside the point. Under the heading "Asbestos as Heat Insulation in Steel Moulding", the report contained at p 70 a passage quoted by the trial judge at [176] and set out at [164] above. 188 In considering whether the risk posed by exposure to asbestos dust was foreseeable, the trial judge noted at [182] the reasoning of Bryson JA in Seltsam Pty Ltd v McNeill [2006] NSWCA 158; 4 DDCR 1 at [36] with respect to the need to identify a class of persons who might be exposed to asbestos dust in the course of industrial operations. This approach had been accepted in McPherson's Ltd v Eaton [2005] NSWCA 435; 65 NSWLR 187 and, more recently, in Caltex Refineries (Qld) Pty Ltd v Stavar [2009] NSWCA 258; 75 NSWLR 649. In this, his Honour was correct. While the evidence available in 1953 might not have demonstrated a significant risk to persons exposed to low levels of dust on rare occasions, such as in the course of home renovations, the risk of exposure in an industrial setting where the exposure was likely to be encountered weekly, daily or more often, over months or years, and the need to take precautions against the risk of serious injury was, by 1953, well-supported in the evidence. The articles to which his Honour referred were capable of supporting the relevant inferences. The volume of additional material contained in the evidence, including expert assessments of additional material which was not in the evidence, also supported the relevant inferences. Ground 12(a) in the Amaca notice of appeal is rejected. (8) Duty of care: foreseeability – Amaba: ground 12 189 Amaba's amended notice of appeal differed from that of Amaca in a number of minor respects. First, and most importantly, reference was made to other dates. Amaba produced products used by the respondent between 1962 and 1983. Accordingly, the point of time that foreseeability that an automotive mechanic could suffer injury was identified as being "from 1962, or at any time prior to 1962 to 1983". At [198], his Honour held: "In 1962 it was reasonably foreseeable by Amaba that an automotive mechanic who worked on brake linings over many years may contract an asbestos related disease." 190 Secondly, there was no complaint of lack of adequate reasons in respect of the finding regarding Amaba, but rather a complaint as to a finding of "actual knowledge of the specific risk of contracting mesothelioma in the absence of any evidence to support such a finding": ground 12(e). 191 In addition to the earlier material referred to in relation to Amaca, his Honour also referred to an article, "Complications of Asbestosis" (30 April 1960, British Medical Journal at p 1345, identifying mesothelioma of the pleura as a specific hazard in respect of a person who has worked in asbestos dust. The article stated (at 1351) that "asbestos dust is most toxic and the amount needed to cause asbestosis is not known so constant vigilance and new preventive measures are needed if this disease is to be abolished": quoted by the primary judge at [187]. 192 There is no need, in the light of the previous finding, to deal with all the specific criticisms made by Amaba in relation to the additional and later material. The criticisms are, for the most part, without substance. Thus, an article is dismissed as apparently irrelevant (though that is not always expressly stated) if it referred to the hazards of asbestos dust, without expressly referring to automotive mechanics working with brake linings. In effect, this criticism confused two separate issues. The first was whether there was available to a specialist manufacturer of asbestos products, such as Amaba (or Amaca), information making it foreseeable that exposure to asbestos dust might involve risks to the health of workers so exposed. A second and separate issue was whether workers in a particular occupation were so exposed. As will be noted below, the negligence of the appellants was identified as the failure to give a warning. Whether or not such a warning should have accompanied brake linings depended on (a) whether it was reasonably foreseeable that those automotive mechanics responsible for removing and fitting brake linings would be exposed to asbestos dust and, (b) whether such exposure carried with it a risk to health. No issue is raised on the appeal (or it appears below) as to the knowledge of Amaca or Amaba in respect of the industrial processes engaged in by automotive mechanics removing and fitting brake linings. There is no complaint that his Honour could not have found that it was reasonably foreseeable to Amaca and Amaba that automotive mechanics undertaking that task would be exposed to asbestos dust. Accordingly, it was open to his Honour to find that the risks to health were foreseeable on the basis of material which did not relate specifically to automotive mechanics. 193 Three further articles were referred to by the trial judge which bore dates between 1953 and 1962: judgment at [173]-[179]. One, "Dust Hazard in Industry", attributed to editorial staff, appeared in an Australian trade journal known as Manufacturing and Management, published 10 July 1956: at [178]. It referred to a study undertaken by the Industrial Hygiene Division of the Victorian Health Department under the supervision of Dr D L G Thomas. Under the heading "Asbestos" it referred to asbestosis, of which it said at p 21: "People prone to the disease are those handling asbestos in its raw state or processing it to make lagging materials; also operatives sawing and cutting any finished product containing asbestos such as brake linings, asbestos sheeting and various insulating materials. Dismantling old dry lagging is a hazardous occupation. Once established, asbestosis constitutes a grave threat to life and health." 194 Amaba's submission in relation to this material included the following statement: "Although there is a reference of a risk to persons 'sawing and cutting … brake linings', these are manufacturing processes, and are not part of the ordinary tasks of an automotive mechanic." 195 This submission was mischievous. By leaving out the words "any finished product containing asbestos" the submission sought to diminish the relevance of the statement in a manner which the respondent described as "misconceived". In its written reply, Amaba neither sought to explain its submission, nor did it concede error. 196 Amaba further complained that the author of the article was "unidentified" and that there was no evidence as to the circulation of the journal. Both those statements were true, but largely beside the point. The authority underlying the content derived from the study undertaken by Dr Thomas, who was identified. Furthermore, the exhibit contained a newspaper article, apparently published at about the same time, referring to the report. On July 11, 1956, the Victorian Government proclaimed that trades, including "Asbestos works or factories in which asbestos is used, manipulated, crushed or pulverized"; which unless preventative measures are adopted may become dangerous to the health of persons employed" are to be dangerous trades within the meaning of the Health Act 1928: Victorian Government Gazette No 721, at 3965. 197 Finally, Dr Thomas published an article himself "Pneumonokoniosis in Victorian Industry" 19 January 1957 in the Medical Journal of Australia ("MJA"), p 75 to similar effect. Dr Thomas referred to a survey of asbestosis in various occupations including "sawing, cutting and finishing any product containing asbestos – for example, brake linings ….": MJA, p 76. The appellants correctly noted that his Honour misquoted this passage at [179], substituting "fitting" for "finishing". However, it does not follow that the article was "plainly directed at manufacturing processes", or that his Honour "misunderstood the article", or that he "mistakenly thought [it] referred to the work of mechanics": Amaba submissions, par 13. In context, sawing and cutting a product containing asbestos could undoubtedly include automotive work. Finishing is equally ambiguous. An available inference, drawn by his Honour, was that work with asbestos products which released dust was hazardous work. 198 On 18 March 1957 it is clear that the MJA article by Dr Thomas was in the hands of Amaca. A memorandum by Mr Hooper stated "I do not think there is anything in this which we do not already know". (His Honour referred to the memorandum at [180], attributing it to Mr Gilbert, but nothing turned on that error: Tcpt, 03/09/10, p 6 (40).) In fact, it might also be noted that Dr Thomas was referred to by Mr Hooper as "our friend", from which it might readily have been inferred that Amaca was aware of Dr Thomas and his study from an earlier point in time. 199 Although Amaba's written submissions made the point that the author of the note worked for Amaca and not Amaba, his Honour did not make a mistake in that respect. It was open to infer from the fact that Amaca had actual knowledge of the article and found nothing new in it, that Amaba would also have knowledge of a risk identified in the same terms. In his written submissions, the respondent stated at par 10: "Amaca's knowledge is relevant to an analysis of foreseeability in the case against Amaba. From its creation in 1962 Amaba (formerly known as Jesakarb [sic]), and Amaca had a symbiotic relationship, Amaca being the major shareholder in Amaba. There was a steady flow of information between the two. Dr McCullagh (Amaca's medical officer) provided medical and scientific advice to Amaba and regularly examined the Amaba workforce." 200 The submission was extensively footnoted by reference to the evidence. There was no contradiction in Amaba's reply. In the course of oral argument, senior counsel for Amaca and Amaba was asked what was known of the relationship between Amaca and Amaba and did not contradict the respondent's written submission: Tcpt, 3/09/10, p 8. 201 The trial judge referred to an article by P.B.S. Fowler, J.C. Sloper, E.C. Warner, "Exposure to Asbestos and Mesothelioma of the Pleura" in the British Medical Journal, (25 July 1964), p 211, reporting on two cases of mesothelioma of the pleura, associated with asbestos exposure. He continued at [189]: "A copy of this article was, on 2 February 1965, forwarded by Professor Brian Gandevia to Mr E T Pysden, the personnel manager of James Hardie and Coy. On 16 February 1965 Mr Pysden wrote to Mr J B Reid, a director of James Hardie and Coy, saying of an article enclosed with the letter: 'The article is not new – it is merely one of many reports in world studies which have been conducted since 1935 when the association between exposure to dust and carcinoma of the lung, mesothelioma of the pleura, tumour of the bladder and uterus and other fatal complications was first recognised.'" 202 Although James Hardie & Coy is now Amaca, his Honour noted that the documents were discovered by Amaba. 203 Essentially, Amaba's argument was misconceived. If it had been suggested that all of this material should be rejected as irrelevant, the objection would no doubt have been dismissed out of hand. All of this material provides evidence capable of supporting the inferences drawn by the trial judge. The complaints now made relate to the manner in which he dealt with the material in his reasons. Where there is evidence capable of supporting an inference and the inference is drawn, further objection will usually be properly dismissed as a challenge to the fact-finding process. In this case, ground 12(e) is rejected. (9) Duty of care – content of duty: grounds 13-15 204 The grounds of appeal were – "13 The trial judge erred in point of law in (implicitly) deciding that Amaca owed the plaintiff (some kind of unspecified) duty of care, (a) Because no risk was reasonable foreseeable, no duty was owed; (b) Although the trial judge found that some risks were foreseeable, no finding was made that Amaca knew or ought to have known of the risks; [This appeal ground is only found Amaca's notice of appeal.] (c) As a consequence of failing to find whether Amaca owned the plaintiff a duty of care, the Trial Judge failed to give any, or any adequate, reasons why, or from when, a duty of care was owed. 14 The trial judge erred in point of law in failing to determine (at all), and, in particular, to determine prospectively, the content of any duty of care which might have been owed by Amaca to the plaintiff at a point in time. 15 The trial judge erred in point of law in (implicitly) deciding that Amaca owed the plaintiff a duty of care when an injury to the plaintiff was not foreseeable." 205 The appellant complained that there was no express finding of duty, nor was the content of the duty determined. There were several parts to this complaint. First, the complaint that there was no specific finding must be addressed. Even if that were correct, as the authorities make clear, the duty imposed on a relevant defendant is a duty to exercise reasonable care towards an individual or class of individuals which includes the plaintiff. None of this was in dispute, other than the foreseeability of injury. 206 The first basis on which the appellants complained of the finding (implicitly) in respect of duty was that no risk was reasonably foreseeable: ground 13(a). This matter has been disposed of by the foregoing reasoning and is rejected. 207 The second basis was that even though some risks were foreseeable, there was no finding that Amaca knew or ought to have known of the risks. (No similar complaint was made in respect of Amaba, presumably because, at [198]-[199], his Honour expressly stated that the relevant risk was "reasonably foreseeable by Amaba" and that "Amaba ought to have known …".) However, his Honour's finding was expressed in terms of that which was "reasonably foreseeable by Amaca": at [186]. 208 In its written submissions at par 102, Amaca carefully explained: "There is no finding that Amaba (and, by implication, Amaca) 'ought to have known' of any risk before 1965. The only finding is that a risk was reasonably foreseeable – a finding which is insufficient to trigger the existence of a duty of care." 209 The complaint at par 102 of the submissions was that a finding that a risk was foreseeable by Amaca did not include a finding that Amaca ought to have known of the risk. That submission does not demand further consideration. The further submission that there was no "finding of fact" to support the existence of a duty of care on the part of Amaca also requires no response, in the light of the finding that the relevant risk was reasonably foreseeable by Amaca from the beginning of the relevant period. Finally, Amaca submitted that the judge failed to provide adequate reasons for a finding as to why Amaca "ought to have been aware of the material to which reference was made": written submissions, par 104. A similar complaint was made in respect of Amaba's ground 13(c). 210 At [200] the trial judge stated: "200. It follows from the above findings that the law imposed a duty upon Amaca and Amaba to take reasonable precautions to prevent Mr Booth suffering harm in consequence of using their products. 201. The scope of the duty depends upon the nature and extent of the risk. This calculus weighs the magnitude of the risk against the gravity of its consequence. 202. In matters of occupational health and safety there are no greater consequences than death. 203. It was known before 1953 that asbestosis was incurable. … 204. In cases of mesothelioma death is most often accompanied by exquisite physical and mental suffering. 205. It is appropriate to impose upon a manufacturer of asbestos products a duty to take strong measures to obviate these consequences, notwithstanding any countervailing commercial interest." 211 It is arguable that only [200] deals with the imposition of a duty, but it does so in express terms. The suggestion that his Honour did not make a finding with respect to duty is rejected, and his reasons were adequate. 212 It remains to address the failure to determine the scope or content of the duty of care. The submissions for the appellant stated that "[t]he legal obligation is substantive – the failure to identify 'with the necessary precision, by reference to the considerations of the nature of those indicated in Wyong Shire Council' is an error of law": par 105. The reference for that proposition was given as Graham Barclay Oysters Pty Ltd v Ryan [2002] HCA 54; 211 CLR 540 at [192] (Gummow and Hayne JJ). This submission is based on a misconception. 213 In Graham Barclay Oysters at [106] McHugh J stated: "The duty of care owed by a manufacturer or producer to a consumer is a duty to take reasonable care to avoid injury to the consumer. To formulate the duty in more specific terms invites error because it is likely to mix a question of law (whether a duty existed) with a question of fact (whether a breach occurred). If the duty is formulated in specific terms, the issue on breach is whether the duty has been performed in accordance with the terms of the duty as formulated. But, as Wyong Shire Council v Shirt shows, the question of breach is far more complex than an affirmative or negative answer to the question whether the defendant carried out the duty as formulated." 214 At [187], in terms consistent with the reasoning of McHugh J set out above, Gummow and Hayne JJ stated: "The Barclay companies concede that they owed a duty of care to their consumers, including Mr Ryan, to take reasonable care to ensure that the oysters they harvested and supplied were safe for human consumption. The immediate issue before this Court is whether the companies breached that duty." 215 Their Honours continued at [192] in the following terms: "A duty of care that is formulated retrospectively as an obligation purely to avoid the particular act or omission said to have caused loss, or to avert the particular harm that in fact eventuated, is of its nature likely to obscure the proper inquiry as to breach. That inquiry [ie as to breach] involves identifying, with some precision, what a reasonable person in the position of the defendant would do by way of response to the reasonably foreseeable risk. … The trial judge and the majority of the Full Court in the present case failed to identify with the necessary precision, by reference to considerations of the nature of those indicated in Wyong Shire Council , the reasonable response to the risk of harm that existed." 216 To suggest that the passage cited in the submissions related to the establishment of the duty, is to reverse the purpose of their Honours' statement. The content of the duty of care, as expressed in its formulation, was to take reasonable care to avoid the risk of foreseeable injury to the class of persons of which Mr Booth was a member. The content in the different sense of what was required of Amaca and Amaba to discharge the duty of care arose in connection with breach of duty, and is further considered under that heading. (10) Breach of duty: ground 16 217 It is not always easy to formulate a decision in point of law when challenging a finding of breach of duty. As appears from Amaca's ground 16, the appellants struggled in this regard: "16 The trial judge erred in point of law in deciding that Amaca had breached a duty of care in the context of (erroneously) finding that a duty of care existed, and in the absence of determining the content of any duty of care. Particulars (a) The trial judge erred in point of law when (implicitly) deciding that Amaca breached a duty of care which it owed to the plaintiff when an injury was not foreseeable; (b) The trial judge did not determine the content of the duty of care, but left the matter only at the level of generalisations such as a need "to take reasonable precautions" or "a duty to take strong measures" (see judgment at [200] and [205]); (c) The trial judge misapplied, or failed to apply, Wyong v Shirt in determining breach of duty; (d) The trial judge failed to make necessary findings as to why a differently worded warning would have produced a different result." 218 The formulation of ground 16 in the Amaba appeal was not materially different. 219 The chapeau provides no detail as to the nature of the complaint. Particular (a) complains again that injury was not foreseeable. This matter has been disposed of by the earlier reasons and must be rejected. Particulars (b) and (c) will be addressed below. Particular (d) is in fact directed to causation, rather than breach. It will nonetheless be addressed. 220 The appellants' submissions complained that there can be an error of law in addressing breach without weighing competing considerations in accordance with the principles identified in Wyong Shire Council v Shirt [1980] HCA 12; 146 CLR 40. It may be accepted, at a level of generality, that failure to identify and apply the correct legal principles involves an error of law. However, such an error is not established by noting that there was no reference to a particular case, nor by a conclusory statement that the relevant considerations were not addressed. Those considerations include what, prospectively, would have been considered reasonable precautions by a person in the place of the appellants; an assessment of the nature and extent of the risk involved, including the magnitude of the risk and the gravity of the consequences if the risk materialised; against those considerations it may be necessary to weigh countervailing commercial interest, reflected in the cost of the precautions. All of those factors were identified by the trial judge in his reasons. All of those factors were relevant in accordance with general law principles. To say that those principles were not considered "at all" is simply fallacious: Amaca's written submissions, par 112. 221 The second arm of the complaint, as identified in the written submissions, was that his Honour took into account irrelevant considerations. The considerations formed part of the trial judge's assessment of the warning he thought should have been given in order to discharge the appellants' duty. 222 The first irrelevant consideration is said to have been the following statement at [213]: "In written submissions, counsel for Amaba says that the alternative, a warning in graphic terms, or a warning of possible death is not a warning: in practical terms it would prevent the product being used. " 223 His Honour, in this paragraph was merely recording a submission that had been made to him. In this Court, the appellant treated the paragraph as if it was a finding by his Honour. It was not, and accordingly the appellant's submission in respect of this paragraph of his Honour's judgment should be rejected. 224 The second irrelevant consideration was said to be a company memorandum of 14 May 1969, referred to by his Honour at [215]. 225 It appears that the appellants did not understand the concept of irrelevant considerations as a basis for asserting an error of law. They are considerations which, on the proper understanding of legal principle, are impermissible. The idea that one can take a single comment out of context in a judgment and declare it irrelevant in that sense defies legal reasoning. Between [206] and [211], his Honour was considering the proper content of an adequate warning. At [206] he set out the terms of the warning which Amaba had adopted in 1978. His Honour considered it inadequate, noting that it "does not even comply with the Code of Practice published by the Asbestos Research Council 10 years earlier, which advised that exhaust ventilation should be provided when grinding brake linings": at [211]. His Honour was entitled to make that comparison. Accordingly, he was entitled to take into account the memorandum of May 1969, in which a director of Amaca proposed issuing a series of bulletins under the suggested heading of "The Asbestos Research Council", providing what the author described as a completely partisan view of the problem. An inference was available from the material that a warning in terms which did not comply with the Asbestos Research Council proposal of 1968 was inadequate. There was no error of law in considering such material. 226 The third irrelevant consideration was to be found in the following paragraph at [216]: "On 14 June 1972 James Hardie's Medical Director, Dr McCullagh, compiled the paper entitled Medical and Hygiene Services-Progress Report which he delivered in a presentation to the chairman and board of directors of James Hardie and Coy. Dr McCullagh wrote: I foresee the time when the sales managers and I will be sitting down to draw up proposals that will protect both our end users and our markets . (Emphasis added)" 227 Again, this statement was made in the context of inadequacies identified in the warning drawn up in 1978. His Honour was entitled (and indeed required) to address Amaba's submission that a warning then under consideration as appropriate would "in practical terms" have prevented "the product being used". The documents of 1969 and 1972 suggest that Amaca was, over many years, concerned that a realistic warning, reflecting the risks perceived, might have a significant, if not dramatic, effect on the market for its products. In considering what was a reasonable response of the company, it was legitimate to take into account those considerations. However, his Honour was not bound by the assessment the company made of that response and was entitled to hold that its response was unreasonable and inadequate. No error of law is demonstrated by indicating disagreement either with his Honour's reasoning or with his conclusion. His conclusion that the warning was entirely inadequate was open on the material before him. 228 It is not correct that, as stated in ground 16(b), the judge "left the matter only at the level of generalizations such as a need 'to take reasonable precautions' or 'a duty to take strong measures'." While the trial judge did use those expressions at [200] and [205], in the following consideration he arrived at a specific form of wording for a warning, set out at [220]. The alleged irrelevant considerations were part of his Honour's finding as to what warning should have been given, in the course of which he held that what had in fact been done was inadequate. This ground of appeal is inexplicable. 229 The submission that the judgment was written in anger, directed against the appellants (submissions, par 118), was inappropriate and should not have been made. It was never withdrawn. The only circumstance in which such a submission could properly be made would be in support of a complaint of bias. No such complaint was made. Grounds 16(b)-(c) are rejected. 230 The final ground under this heading, 16(d), related to causation. In the written submissions, after noting the finding that the breach of duty had caused the injury, it was said (par 119): "Here there was a question: would any differently worded warning have been effective? If so, why? The trial judge did not say so. The failure to address the question whether a warning would have been efficacious is an error of law. …The trial judge erred in law in this respect as well." 231 The suggestion that his Honour did not address the question is erroneous; at [221] his Honour concluded in respect of liability: "I find that both Amaca and Amaba failed to discharge their duty to warn Mr Booth of the dangers of asbestos, and that it is because of this failure that he has contracted mesothelioma." 232 It is apparent that there is an elision in the paragraphs leading up to this conclusion. 233 In an affidavit sworn on 18 February 2010, Mr Booth stated: "If only I had been warned about the dangers of asbestos I would have done everything in my power to avoid the dust from brake linings. If I had been warned about the dangers of asbestos dust from brake linings I would never have used compressed air to blow out drums and work benches. I would have worn a mask and used water to clean drums, floors and work benches. The boxes of brake linings that I handled were big enough to accommodate a warning and even a small pamphlet with safety instructions about keeping dust down, wearing a mask and not using compressed air. I am so angry that I was never warned or given the opportunity to protect myself from a substance that I had no idea was carcinogenic." 234 In cross-examination by counsel for the appellants, the following exchanges took place (Tcpt, 22/02/10, pp 47-50): "Q. I heard you say that you did not see a warning on the brake packaging while you were working. A ---No I did not. Q. [I] take it what you are really referring to was the potential for somebody to put some kind of warning or caution on the packet itself. A ---Yes. Never saw it. Q. If, for example, if somebody had given you a caution about using a product, would you obey it. A ---Yes. Q. If the caution had told you something, for example, that the product contained asbestos and that breathing asbestos could damage your health, would you have paid attention to that. A ---I would have, yes. Q. What would you have done. A ---Not used that product. … Q. What would you have done if you had been told a product contained asbestos and breathing asbestos can damage your health? What would you have done Mr Booth. A ---Taken some precautions not to breathe that product. Q. Would you have taken the precaution that you'd keep the levels of dust down. A ---Definitely would have kept the levels of dust down. … Q. That's the sort of thing when you see a warning which says a product contains asbestos, breathing asbestos can damage your health, you should keep the dust levels down, that's the kind of warning you would look for. A ---Yes. Q. That would have told you enough, would it. A ---Well that would have told me enough plus I would have been instructed by the mechanic and the company that I worked for to take precautions. … Q. What if a warning said this, you should keep dust down and you should keep dust down by following simple safety rules such as using a damp cloth when removing, servicing or relining brakes. A ---Then that's what would have been done. Q. And what if a warning said you should not use an airline or a brush to remove dust. A ---Then that would not have been done, we would've used the approved method. Q. And by airline they're talking about compressed air thing, is that right. A ---That's right, yes. … Q. And a warning which gave you a reminder, inhaling asbestos can damage your health. A ---We would've worn a mask. Q. I'm going to suggest to you, Mr Booth, that there was such a warning very similar to the words that I've used which was put onto all of the Hardie Ferrodo products that were manufactured from 1978, do you accept that. A ---I've never seen that warning on their products. … Q. Well if that had been on the packet would you have paid any attention to it. A ---Yes. Q. If it was on the packet and you didn't see it are you able to explain how that would come about. A ---No, I'm not. But as I said, I've never seen that on a brake lining box. Q. Could it be the pressure of work. A ---It's always possible. Q. That you didn't – that's possible. Could it be the confined spaces or congested spaces in which you were compelled to work. A ---I don't know. Q. You're not in a position to deny that that warning was on the boxes, are you. A ---Well as I said, I did not see the warning on the boxes. Q. And if you had seen it would you have obeyed it. A ---Yes. Q. So that if that warning had been there you would have done what the warning said, taken those measures. If you need to read please do so. A ---Yes. Q. So that warning would have been effective in conveying to you a risk associated with inhaling asbestos. A ---Yes. Q. And it would have been effective in conveying to you that you should follow safety measures to reduce the dust. A ---Yes. Q. It would have been completely effective and alerted you to the problem of using asbestos brakes. A ---It would have but I would have expected the printing to be a lot larger than that to make it obviously visible quickly. Q. Well irrespective of its size, that message contained in that warning would have been effective in alerting you to the risks associated with inhaling asbestos. A ---Yes. Q. And it would have been effective in alerting you to take measures to avoid inhaling the dust, is that right. A ---That's right. Q. And the reason why it would have been effective is because it would have conveyed to you that inhaling asbestos dust can be dangerous. A ---Yes. Q. And you would have understood that by looking at the warning. A ---Yes. Q. Dangerous meaning dangerous to your health, is that right. A ---That's right." 235 The purpose of this cross-examination was self-evident. Although Mr Booth gave evidence that he would have abided by the directions contained in a warning, he had no recollection of and did not abide by the directions in fact contained in the warning on brake lining boxes from 1978. It was submitted to the trial judge that it was inconceivable that Mr Booth did not see the warnings, and that the only explanation was that he 'had no or scant regard to them'. (In fact, the cross-examination was not soundly based in that the evidence was not of warnings on boxes, but of warnings on small slips inside the boxes; for present purposes that may be passed over.) 236 The judge dealt with this material in the following passages: "217. Mr Booth, who continued working with the brakes until 1983, does not recall seeing the warning slips included in the packaging after 1978. It may be that, because the warnings were not printed on the outside of the boxes containing the brake linings, the slips were not obvious, but mixed in with packaging material. It may be that Mr Booth read one such slip, dismissed the warning as unimportant, and has now forgotten that he ever read it. The necessary purpose of a warning being graphic is that it should arrest the attention of the reader. 218. Although Mr Booth had no memory of reading the warning slips included in the packaging of brake linings, in cross examination he conceded that had he seen a warning that breathing asbestos could damage his health he would have taken action to keep the levels of dust down. 219. I do not think that this concession assists Amaba's case. First because I find that the asbestos fibres liberated from Amaba's brake linings before 1978 materially contributed to Mr Booth's disease, and secondly because I am not persuaded that the warning given by Amaba was adequate to enter the consciousness of Mr Booth as a warning of sufficient threat to require precautions." 237 The trial judge found that the warning given from 1978 was inadequate, because it was not in sufficiently graphic terms to arrest the attention of the reader and because it was not sufficiently visible. Although in respect of the actual warning Mr Booth's evidence constituted a 'concession' potentially in Amaba's favour, in respect of any better warning, it provided evidence of causation. This was implicit in his Honour's acceptance of the 'concession' and the manner in which he dealt with it. Had there been a better warning, one which arrested Mr Booth's attention, he would have taken note of it and abided by it. 238 Whether the reasoning in favour of causation (which was expressly found) could have been better expressed is beside the point in an appeal of the kind presently before this Court. No error of law has been demonstrated in respect of this issue. Ground 16(d) is rejected. (11) Damages: ground 17 239 Ground 17 raised a short point with respect to the entitlement of the respondent to damages for domestic care and assistance. The ground contained two particulars: "(a) the trial judge erred by referring to ss 59 and 60 of the Workers Compensation Act 1987 , and the cases decided under that section [sic], before they were amended; (b) the trial judge erred in law in failing to apply (or even refer to) s 60AA of the Workers Compensation Act 1987 ." 240 His Honour awarded an amount of $5,000 in relation to past domestic assistance and $50,000 in relation to future domestic assistance. In doing so, he referred to ss 59 and 60 of the Workers Compensation Act 1987 (NSW), which provided an entitlement to compensation for the cost of medical or related treatment. He referred to authority for the proposition that services performed voluntarily or gratuitously are not covered by s 60: at [232]. 241 The reference to amendment was presumably to amendment at the time s 60AA was added. It is not correct that the trial judge referred to ss 59 and 60 before they were amended. Section 59 is a definition section, and the trial judge set out paras (f) and (f1) in their amended form. He said of s 60 that it "provides that a worker is entitled to be paid for the cost of medical or related treatment", which as a general description was correct for its post-amendment form. 242 Section 60AA, which came into operation in 2002, imposes an obligation on a worker's employer to pay for domestic assistance, in addition to any other compensation payable under the Act, but for gratuitous domestic assistance only if the person providing the assistance has lost income or foregone employment as a result of providing the assistance and if the assistance is provided in accordance with a care plan established by the insurer: s 60AA(3). 243 It is true, as the appellants submitted, that his Honour did not refer to s 60AA of the Workers Compensation Act. 244 There are at least two problems with the appellants' submissions. First, payments under s 60AA are to be made to the provider of the assistance and not to the injured worker: s 60AA(5)(c). Secondly, the aforementioned conditions of engagement of s 60AA were not demonstrated on the evidence, that is, the lost income or foregone employment and the care plan. If there was, objectively, no reason to suppose that an entitlement had arisen under s 60AA, or had been shown to be likely to arise in the future, his Honour could properly have ignored it as irrelevant. 245 The respondent submitted that this was a matter upon which the appellants bore the onus of proof, referring to Downes v Amaca Pty Ltd [2010] NSWCA 76 at [21]-[22]. Neither in this Court, nor before the trial judge, did the appellants refer to any evidence that would have engaged the factual precondition of the operation of s 60AA. Accordingly, the appellants have not demonstrated that his Honour erred in law in failing to refer to the possibility of compensation being payable, nor in awarding compensation to the respondent under this head of loss. (12) Conclusions 246 The appellants have been unsuccessful in respect of each of their grounds of appeal. The appeals must each be dismissed; the appellants must pay the respondent's costs. 247 The appellants have not demonstrated any basis for the grant of relief under s 69 of the Supreme Court Act. Each summons must be dismissed with costs. ********** DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. 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